Roche Molecular Systems, Inc. v. Cepheid ( 2018 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    ROCHE MOLECULAR SYSTEMS, INC.,
    Plaintiff-Appellant
    v.
    CEPHEID,
    Defendant-Appellee
    ______________________
    2017-1690
    ______________________
    Appeal from the United States District Court for the
    Northern District of California in No. 3:14-cv-03228-EDL,
    Magistrate Judge Elizabeth D. Laporte.
    ______________________
    Decided: October 9, 2018
    ______________________
    STEPHEN S. RABINOWITZ, Hughes Hubbard & Reed
    LLP, New York, NY, argued for plaintiff-appellant. Also
    represented by JAMES W. DABNEY, MITCHELL EPNER,
    PATRICE POLYXENE JEAN, DAVID E. LANSKY, LYNN M.
    RUSSO.
    ERIK R. PUKNYS, Finnegan, Henderson, Farabow,
    Garrett & Dunner, LLP, Palo Alto, CA, argued for de-
    fendant-appellee. Also represented by MICHAEL PAUL
    BARKER; GRANT L. KIM, WESLEY ELLSWORTH OVERSON,
    Morrison & Foerster LLP, San Francisco, CA.
    ______________________
    2                 ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    Before O’MALLEY, REYNA, and HUGHES, Circuit Judges.
    Opinion for the court filed by Circuit Judge REYNA.
    Concurring opinion filed by Circuit Judge O’MALLEY.
    REYNA, Circuit Judge.
    Appellant Roche Molecular Systems, Inc. (“Roche”)
    owns 
    U.S. Patent No. 5,643,723
     (“the ’723 patent”), titled
    “Detection of a Genetic Locus Encoding Resistance to
    Rifampin in Microbacterial Cultures and in Clinical
    Specimens.” The United States District Court for the
    Northern District of California found that the asserted
    claims of the ’723 patent are directed to patent-ineligible
    subject matter and are therefore invalid under 
    35 U.S.C. § 101
    . Roche appeals from a grant of summary judgment
    of invalidity. We affirm.
    I.   THE ’723 PATENT
    The ’723 patent is directed to methods for detecting
    the pathogenic bacterium Mycobacterium tuberculosis
    (“M. tuberculosis” or “MTB”). ’723 patent col. 2 ll. 50–54.
    MTB infection is a major cause of tuberculosis. 
    Id.
     col. 1
    ll. 13–30. In 1994, before the priority date of the ’723
    patent, the general method of MTB detection in a tubercu-
    losis patient was known as sputum examination by the
    acid-fast bacilli smear. For this test, a biological sample
    taken from a patient is subjected to cell culture in a
    process that can take three to eight weeks. 
    Id.
     col. 2 ll. 9–
    11. This test has limitations: it can identify the presence
    of bacterial cells in a biological sample, but cannot identi-
    fy the cells as MTB. There is a need to know whether the
    MTB from a patient is resistant to antibiotics. The
    standard of care for MTB treatment at the time involved a
    regimen of antibiotics, with rifampin being a first-line
    anti-tuberculosis drug. 
    Id.
     col. 1 ll. 31–33. Tuberculosis
    outbreaks, however, still resulted because of delays in
    diagnosis and reporting of rifampin-resistant tuberculosis
    ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID                  3
    due to the inability to rapidly identify MTB strains that
    are resistant to rifampin and put a patient on an appro-
    priate alternative therapy. 
    Id.
     col. 1 ll. 61–65.
    Prior to the ’723 patent, scientists in the field had
    been working on diagnostic tests for faster detection of
    MTB, particularly rifampin-resistant MTB strains. 
    Id.
    col. 2 ll. 18–46. It was speculated that “[g]enotypic detec-
    tion of multi-drug resistant MTB [strains] directly from
    clinical specimens is theoretically the fastest and most
    direct step toward determining effective therapy for
    patients.” 
    Id.
     col. 2 ll. 39–42. It was known in the art
    that rifampin has a unique site of action on a particular
    gene that encodes the β subunit of bacterial RNA poly-
    merase (“the rpoB gene”). 
    Id.
     col. 1 ll. 31–42. The rpoB
    gene is present in MTB and other bacterial species, and
    its deoxyribonucleic acid (“DNA”) sequences were known
    to be highly conserved, with little variation from one
    bacterial species to another. In 1994, single site muta-
    tions in the rpoB gene that confer rifampin resistance in
    some bacteria, such as Escherichia coli (“E. coli”), were
    well characterized, making rpoB a prime candidate for
    studying rifampin resistance in MTB. 
    Id.
     col. 1 ll. 42–52.
    The inventors of the ’723 patent—scientists from
    Roche and the Mayo Foundation for Medical Education
    and Research (“Mayo”)—sequenced the rpoB gene from
    various bacteria species, including MTB, obtained from a
    commercial vendor. 1 
    Id.
     col. 8 ll. 1–3 and col. 8 l. 15–col. 9
    l. 20. After comparing rpoB DNA sequences across differ-
    ent species, the inventors discovered that the rpoB gene
    in MTB contains eleven “position-specific ‘signature
    nucleotides’” (i.e., naturally occurring single nucleotide
    1  Mayo later assigned its rights in the ’723 patent to
    Roche. See Roche Molecular Sys., Inc. v. Cepheid, No. 14-
    CV-03228-EDL, 
    2017 WL 6311568
    , at *1 (N.D. Cal. Jan.
    17, 2017).
    4                 ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID
    mutations) that are only present in MTB but not in other
    bacteria. 
    Id.
     col. 2 l. 60–col. 3 l. 2. In other words, these
    naturally occurring signature nucleotides are like finger-
    prints of MTB: if an investigator detects one of the eleven
    signature nucleotides from a biological sample, she knows
    the sample contains MTB, and vice versa. These signa-
    ture nucleotides, therefore, could be used to identify MTB
    using genetic testing, which is both faster and more
    accurate than the traditional MTB detection methods. 
    Id.
    col. 2 ll. 9–31.
    Based on these eleven MTB-specific signature nucleo-
    tides, the Roche inventors devised a diagnostic test that
    could (1) identify whether or not a biological sample
    contains MTB, and (2) if MTB is present, predict whether
    that MTB is a strain that is resistant to rifampin treat-
    ment. The diagnostic test of the ’723 patent involves
    subjecting DNA extracted from a biological sample taken
    from a patient (e.g., a tissue or fluid sample) to amplifica-
    tion by polymerase chain reaction (“PCR”) using a short,
    single-stranded nucleotide sequence (a “primer”) that can
    hybridize (i.e., bind) to at least one of the eleven position-
    specific signature nucleotides in the MTB rpoB gene.
    PCR is a method of amplifying DNA exponentially.
    See Roche, 
    2017 WL 6311568
    , at *2. In PCR, a pair of
    primers effectively “flanks,” or marks the start and finish
    of, the DNA segment—e.g., the rpoB gene or a portion of
    it—to be copied. Strands of DNA are then replicated
    between the primer pair by a DNA polymerase. This
    process is repeated until a sufficient number of copies of
    the desired DNA segment are generated. These copies,
    known as “amplification product,” make it possible to
    detect whether a specific type of DNA is present. 
    Id.
     It is
    undisputed that by the time of the invention in 1994, PCR
    had become a well-understood, routine, and conventional
    technique. 
    Id.
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID                5
    After PCR is performed, the presence of DNA amplifi-
    cation product in sufficient copies from the reaction
    indicates that MTB is present in the biological sample.
    The absence of DNA amplification product (i.e., below the
    detection limit using standard assays) indicates that MTB
    is absent from the biological sample. The amplified rpoB
    DNA segment from the PCR can, in turn, be tested for the
    presence of known genetic mutations associated with
    rifampin resistance. Thus, the ’723 patent represents an
    improvement over the traditional sputum examination
    method for detecting MTB, as its genetics-based diagnos-
    tic method is faster and more accurate.
    The ’723 patent provides two types of claims: (1) com-
    position-of-matter claims for the primers used in the PCR,
    which could hybridize to the rpoB gene of MTB at a site
    that includes at least one of the eleven signature nucleo-
    tides (“the primer claims”); and (2) process claims for
    methods for detecting MTB that include amplifying target
    sequences by PCR and detecting amplification products,
    which, if present, indicate the presence of MTB (“the
    method claims”).
    Claims 1–13 are the method claims. Claim 1, the sole
    independent method claim, recites:
    1. A method for detecting Mycobacterium tubercu-
    losis in a biological sample suspected of containing
    M. tuberculosis comprising:
    (a) subjecting DNA from the biological
    sample to polymerase chain reaction
    [PCR] using a plurality of primers under
    reaction conditions sufficient to simplify a
    portion of a M. tuberculosis rpoB [gene] to
    produce an amplification product, wherein
    the plurality of primers comprises at least
    one primer that hybridizes under hybrid-
    izing conditions to the amplified portion
    of the [gene] at a site comprising at least
    6                ROCHE MOLECULAR SYSTEMS, INC.     v. CEPHEID
    one position-specific M. tuberculosis sig-
    nature nucleotide selected, with reference
    to FIG. 3 (SEQ ID NO: 1), from the group
    consisting
    a G at nucleotide position 2312,
    a T at nucleotide position 2313,
    an A at nucleotide position 2373,
    a G at nucleotide position 2374,
    an A at nucleotide position 2378,
    a G at nucleotide position 2408,
    a T at nucleotide position 2409,
    an A at nucleotide position 2426,
    a G at nucleotide position 2441,
    an A at nucleotide position 2456, and
    a T at nucleotide position 2465; and
    (b) detecting the presence or absence of an
    amplification product, wherein the pres-
    ence of an amplification product is indica-
    tive of the presence of M. tuberculosis in
    the biological sample and wherein the ab-
    sence of the amplification product is indic-
    ative of the absence of M. tuberculosis in
    the biological sample.
    ’723 patent col. 25 l. 57–col. 27 l. 6. 2 Dependent claims 2–
    13 add various limitations to claim 1 concerning PCR,
    PCR analysis, and primer preparation details.
    2  Adenine (“A”), Thymine (“T”), and Guanine (“G”),
    together with Cytosine (“C”), constitute the four nucleo-
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID                7
    Claims 17–20 are the primer claims.       Independent
    claim 17 is representative and recites:
    17. A primer having 14–50 nucleotides that hy-
    bridizes under hybridizing conditions to an M. tu-
    berculosis rpoB [gene] at a site comprising at least
    one position-specific M. tuberculosis signature nu-
    cleotide selected, with reference to FIG. 3 (SEQ ID
    NO: 1), from the group consisting of [the same 11
    nucleotides at the positions disclosed in claim 1].
    
    Id.
     col. 28 ll. 14–31. Dependent claims 18–20 each add
    further limitations. 3 
    Id.
     col. 28 ll. 32–46. Dependent
    claim 20, for example, discloses full DNA sequences of
    certain primers. 
    Id.
     col. 28 ll. 44–46.
    II. DISTRICT COURT PROCEEDING
    Appellee Cepheid makes and sells “Xpert® MTB/RIF
    Assay,” an assay that can detect MTB in a biological
    sample and can identify rifampin-resistant MTB. Roche
    brought a patent infringement case against Cepheid
    asserting that Cepheid’s product infringed the ’723 pa-
    tent. Roche, 
    2017 WL 6311568
    , at *1. Cepheid filed a
    motion for summary judgment, arguing that all of the
    asserted claims claim patent-ineligible subject matter
    under 
    35 U.S.C. § 101
    . 
    Id. at *9
    .
    The district court granted Cepheid’s motion. 
    Id. at *19
    . The district court found that the primer claims of the
    ’723 patent, “which have genetic sequences identical to
    those found in nature, are indistinguishable from those
    held to be directed to nonpatentable subject matter” and
    tide building blocks of DNA. See Roche, 
    2017 WL 6311568
    , at *2.
    3   The remaining claims of the ’723 patent, claims
    14–16 and 21–23, are also primer claims, but they are not
    asserted in this litigation.
    8                ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    are thus invalid. 
    Id. at *14
    . The district court also found
    that the method claims are invalid because they are
    directed to “nonpatentable laws of nature or natural
    phenomena” and “the use of newly developed, non-
    patentable primers to bind to newly identified naturally
    occurring signature nucleotides . . . using the well-known,
    routine process of PCR in a conventional way does not
    transform the claimed methods into” patent-eligible
    subject matter. 
    Id.
     at *16–17.
    Roche timely appealed. We have jurisdiction under 
    28 U.S.C. § 1295
    (a)(1).
    III. DISCUSSION
    We review the grant of summary judgment under the
    law of the regional circuit, in this case the Ninth Circuit.
    Charles Mach. Works, Inc. v. Vermeer Mfg. Co., 
    723 F.3d 1376
    , 1378 (Fed. Cir. 2013). The Ninth Circuit reviews
    the grant or denial of summary judgment de novo. Leever
    v. Carson City, 
    360 F.3d 1014
    , 1017 (9th Cir. 2004). We
    also review de novo the question of whether a claim is
    invalid under 
    35 U.S.C. § 101
    . Voter Verified, Inc. v.
    Election Sys. & Software LLC, 
    887 F.3d 1376
    , 1384 (Fed.
    Cir. 2018).
    The only issues on appeal are whether the aforemen-
    tioned primer claims and the method claims of the ’723
    patent are patent-ineligible within the meaning of § 101.
    Section 101 provides that “[w]hoever invents or discovers
    any new and useful process, machine, manufacture, or
    composition of matter, or any new and useful improve-
    ment thereof, may obtain a patent therefor, subject to the
    conditions and requirements of this title.” 
    35 U.S.C. § 101
    . There are certain exceptions to this provision: laws
    of nature, natural phenomena, and abstract ideas are not
    patent-eligible subject matter. Alice Corp. v. CLS Bank
    Int’l, 
    134 S. Ct. 2347
    , 2354 (2014) (collecting cases).
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID                9
    The Supreme Court has established a two-step
    framework for distinguishing patents that claim laws of
    nature, natural phenomena, and abstract ideas from
    those that claim patent-eligible applications of those
    concepts. 
    Id.
     at 2355 (citing Mayo Collaborative Servs. v.
    Prometheus Labs., Inc., 
    566 U.S. 66
    , 77–79 (2012)).
    Under the Alice/Mayo two-step framework, we first
    “determine whether the claims at issue are directed to one
    of those patent-ineligible concepts.” 
    Id.
     (emphasis added);
    see also Enfish, LLC v. Microsoft Corp., 
    822 F.3d 1327
    ,
    1335 (Fed. Cir. 2016). “[T]he ‘directed to’ inquiry applies
    a stage-one filter to claims, considered in light of the
    specification, based on whether ‘their character as a whole
    is directed to excluded subject matter.’” Enfish, 822 F.3d
    at 1335 (quoting Internet Patents Corp. v. Active Network,
    Inc., 
    790 F.3d 1343
    , 1346 (Fed. Cir. 2015)). At step one,
    “it is not enough to merely identify a patent-ineligible
    concept underlying the claim; we must determine whether
    that patent-ineligible concept is what the claim is ‘di-
    rected to.’” Rapid Litig. Mgmt. Ltd. v. CellzDirect, Inc.,
    
    827 F.3d 1042
    , 1050 (Fed. Cir. 2016).
    If a claim is directed to one of those patent-ineligible
    concepts, we move to step two of the Alice/Mayo inquiry
    to “examine the elements of the claim to determine
    whether it contains an ‘inventive concept’ sufficient to
    ‘transform’ the claimed abstract idea into a patent-eligible
    application.” Alice, 
    134 S. Ct. at 2357
     (quoting Mayo, 
    566 U.S. at
    72–73, 78). At step two, there must be a further
    inventive concept to take the claim into the realm of
    patent-eligibility. 
    Id.
     For claims that encompass natural
    phenomena, the method steps are the “additional features
    that must be new and useful.” Ariosa Diagnostics, Inc. v.
    Sequenom, Inc., 
    788 F.3d 1371
    , 1377 (Fed. Cir. 2015); see
    also Genetic Techs. Ltd. v. Merial L.L.C., 
    818 F.3d 1369
    ,
    1376 (Fed. Cir. 2016), cert. denied, 
    137 S. Ct. 242
     (2016).
    Following the Alice/Mayo framework, we address the
    primer claims and the method claims in turn.
    10               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    A. The Primer Claims
    Roche argues that at Alice/Mayo step one, the primer
    claims (claims 17–20) are patent-eligible because they are
    directed to artificial, man-made primers that are different
    from naturally occurring DNA. Roche, 
    2017 WL 6311568
    ,
    at *10. Specifically, Roche argues that the claimed pri-
    mers have both a 3-prime end and a 3-prime hydroxyl
    group, while the naturally occurring bacterial MTB DNA
    contains neither of these. 
    Id. at *11
    . The district court
    rejected Roche’s arguments and found that “the primer
    claims in this case, which have genetic sequences identi-
    cal to those found in nature, are indistinguishable from
    those held to be directed to nonpatentable subject matter
    in In Re BRCA1.” 
    Id.
     at *14 (citing In re BRCA1- &
    BRCA2-Based Hereditary Cancer Test Patent Litig., 
    774 F.3d 755
    , 760 (Fed. Cir. 2014) (“BRCA1”)). We agree.
    BRCA1 forecloses Roche’s arguments. There, this
    court examined the subject matter eligibility of similar
    primer claims and held that those primers “are not dis-
    tinguishable from the isolated DNA found patent-
    ineligible in Myriad” and thus are not patent-eligible.
    BRCA1, 774 F.3d at 760 (citing Ass’n for Molecular Pa-
    thology v. Myriad Genetics, Inc., 
    569 U.S. 576
    , 591 (2013)).
    It is well established that primers are short, single-
    stranded nucleic acid molecules that bind to their com-
    plementary nucleotide sequence. 4 
    Id. at 761
    ; see Roche,
    
    2017 WL 6311568
    , at *10. As this court found in BRCA1,
    “[p]rimers necessarily contain the identical sequence of
    4  Complementarity refers to the inherent property
    of nucleotides that causes them to pair with each other:
    Adenine pairs with Thymine, and Cytosine pairs with
    Guanine. J.A. 1129–30. This property allows investiga-
    tors who know the sequence of a single strand of DNA to
    accurately predict the sequence of the opposite DNA
    strand. 
    Id.
    ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID               11
    the [nucleotide] sequence directly opposite to the [DNA]
    strand to which they are designed to bind. They are
    structurally identical to the ends of DNA strands found in
    nature.” 774 F.3d at 760. The court further held:
    A DNA structure with a function similar to that
    found in nature can only be patent eligible as a
    composition of matter if it has a unique structure,
    different from anything found in nature. Myriad,
    133 S. Ct. at 2116–17. Primers do not have such a
    different structure and are patent ineligible.
    Id. at 761 (citation omitted).
    It is undisputed that the primers before us have the
    identical nucleotide sequences as naturally occurring
    DNA, just like the primers found subject matter ineligible
    in BRCA1. Appellant Br. 23 (admitting that “the claimed
    primers include DNAs with the same nucleotide sequence
    as portions of the MTB rpoB gene”). Nothing in the ’723
    patent suggests that the Roche inventors introduced any
    mutations that would have made the primers’ nucleotide
    sequences different from those found in nature. Thus,
    Roche’s primers are indistinguishable from their corre-
    sponding nucleotide sequences on the naturally occurring
    MTB rpoB gene.
    Roche argues that the claimed primers are nonethe-
    less patent-eligible because they “are chemically and
    structurally distinct from any nucleic acid that occurs in
    nature or that can be isolated from naturally occurring
    DNA.” Appellant Br. 23. According to Roche, its claimed
    primers have a 3-prime end and a 3-prime hydroxyl
    group, which are absent in naturally occurring DNA.
    This distinction is unavailing. The same argument was
    raised in the opening brief in BRCA1. Roche, 
    2017 WL 6311568
    , at *14 (citing Appellant Br. at 11–12, 65–66,
    BRCA1 
    774 F.3d 775
     (Nos. 14–1361, –1366), 
    2014 WL 1668324
    ). This court rejected this argument, holding that
    the primers at issue were patent-ineligible subject matter.
    12               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    BRCA1, 774 F.3d at 761. As we held in BRCA1, “it makes
    no difference that the identified gene sequences are
    synthetically replicated.” Id. at 760. It was undisputed
    that the primers in BRCA1 contain 3-prime ends and 3-
    prime hydroxyl groups, exactly as Roche’s primers in this
    case. Roche, 
    2017 WL 6311568
    , at *14. Thus, except for
    the nucleotide sequences, the primers before us are not
    chemically or structurally different from the primers that
    we held patent-ineligible in BRCA1.
    Roche also contends that BRCA1 is distinguishable
    because, as a bacterium, MTB has “a circular chromo-
    some, which has neither a 3-prime end nor a 3-prime
    hydroxyl [group],” while “[t]he primers at issue in BRCA1
    were derived from human DNA, in which each chromo-
    some occurs as a linear molecule.” Appellant Br. 23, 31.
    Roche’s emphasis on the chromosome is misplaced. The
    shape of MTB’s chromosomes is not relevant to the in-
    quiry on the subject matter eligibility of the claimed
    primers. As this court determined in BRCA1, the subject
    matter eligibility inquiry of primer claims hinges on
    comparing a claimed primer to its corresponding DNA
    segment on the chromosome—not the whole chromosome.
    774 F.3d at 760–61 (emphasizing the appropriate compar-
    ison being between the primers and “the relevant portion
    of the naturally occurring sequence” (emphasis added)).
    Neither the claims nor the written description of the ’723
    patent contain any reference to the circular nature of
    MTB chromosomes. Indeed, Roche’s expert admitted that
    “whether a chromosome is linear or circular makes no
    difference in designing a primer.” Roche, 
    2017 WL 6311568
    , at *12. Therefore, at Alice/Mayo step one, we
    find that the asserted primers are indistinguishable from
    naturally occurring DNA and that the primer claims are
    directed to a natural phenomenon.
    Roche next argues that its primers can be distin-
    guished from the patent-ineligible primers of BRCA1
    because they can hybridize to only one of eleven position-
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID               13
    specific signature nucleotides on the MTB rpoB gene.
    Appellant Br. 24. This is an Alice/Mayo step two argu-
    ment: Roche is arguing that the specificity of its primers
    to the eleven signature nucleotides would “transform” the
    claimed naturally occurring phenomenon into patent-
    eligible subject matter. But Roche’s emphasis on hybrid-
    izing to particular DNA sequences is unavailing. A
    primer that is otherwise patent-ineligible does not gain
    subject matter eligibility simply because it can selectively
    hybridize to a certain position of naturally occurring
    DNA, because a primer having an identical nucleotide
    sequence to naturally occurring DNA without further
    chemical modification is a natural phenomenon. See
    BRCA1, 774 F.3d at 760. Here, the primers before us
    have no further chemical modification. 5
    The eleven position-specific signature nucleotides on
    the MTB rpoB gene that Roche’s primers are designed to
    hybridize to are naturally occurring; the Roche inventors
    identified these eleven positions after sequencing MTB
    DNA. ’723 patent col. 12 ll. 1–23. In other words, Roche
    identified these pre-existing position-specific signature
    nucleotides; it did not create them. There is no doubt that
    Roche’s discovery of these signature nucleotides on the
    MTB rpoB gene and the designing of corresponding pri-
    mers are valuable contributions to science and medicine,
    5    We do not address the subject matter eligibility of
    primers that have been altered—e.g., investigator-
    induced mutation(s) such that their nucleotide sequences
    are not found in nature, or primers which are chemically
    modified or labeled by investigators such that they cannot
    be isolated directly from naturally occurring DNA. See
    Myriad, 569 U.S. at 596 (“Scientific alteration of the
    genetic code presents a different inquiry, and we express
    no opinion about the application of § 101 to such endeav-
    ors.”).
    14               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    allowing for faster detection of MTB in a biological sample
    and testing for rifampin resistance.              However,
    “[g]roundbreaking, innovative, or even brilliant discovery
    does not by itself satisfy the § 101 inquiry.” Myriad, 569
    U.S. at 591; Ariosa, 788 F.3d at 1379. The primers are
    not patent-eligible because they can be found in nature,
    not because they are not valuable scientific discoveries.
    We hold that the primers before us are indistinguish-
    able from their corresponding nucleotide sequences on the
    naturally occurring DNA, and that the primer claims,
    therefore, are patent-ineligible within the meaning of
    § 101. We next address the asserted method claims.
    B. The Method Claims
    At Alice/Mayo step one, the plain language of the as-
    serted method claims, viewed in light of the written
    description, demonstrates that they are directed to natu-
    rally occurring phenomena. The method claims disclose a
    diagnostic test based on the observation that the presence
    of the eleven position-specific signature nucleotides of the
    naturally occurring MTB rpoB gene indicates the pres-
    ence of MTB in a biological sample. Claim 1, the sole
    independent method claim, provides “[a] method for
    detecting Mycobacterium tuberculosis in a biological
    sample” and contains two steps: (1) PCR amplification of
    DNA (“the amplification step”), and (2) determination of
    the presence of MTB based on the presence or absence of
    PCR amplification product (“the detecting step”). ’723
    patent col. 25 l. 57–col. 27 l. 6. The amplification step
    subjects DNA from a biological sample—naturally occur-
    ring matter—to amplification by PCR using primers that
    are designed to hybridize to at least one of the eleven
    naturally occurring position-specific signature nucleotides
    on the MTB rpoB gene. Id. at col. 25 l. 60–col. 26 l. 67.
    The primers, as discussed above, are indistinguishable
    from their corresponding naturally occurring segments on
    DNA. The detecting step of claim 1 is a mental determi-
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID              15
    nation step: if a PCR amplification product is detected,
    MTB is present in the biological sample, and vice versa.
    Id. at col. 27 ll. 1–6.
    Claim 1 establishes that the method claims are di-
    rected to a relationship between the eleven naturally
    occurring position-specific signature nucleotides and the
    presence of MTB in a sample. In other words, the method
    claims assert that if an investigator detects a signature
    nucleotide from a sample, she knows the sample contains
    MTB. This relationship between the signature nucleo-
    tides and MTB is a phenomenon that exists in nature
    apart from any human action, meaning the method claims
    are directed to a natural phenomenon, which itself is
    ineligible for patenting.
    The written description supports the conclusion that
    the method claims of the ’723 patent are directed to a
    patent-ineligible natural phenomenon. In the Summary
    of the Invention, the patent states:
    This invention involves a comparative analysis of
    the rpoB sequences in MTB, other mycobacteria
    and related . . . bacteria . . . demonstrating the
    heretofore undiscovered presence of a set of MTB-
    specific position-specific “signature nucleotides”
    that permits unequivocal identification of MTB
    ....
    ’723 patent col. 2 ll. 60–65 (emphasis added). The lan-
    guage makes clear what the inventors’ discovery entails:
    the revelation of a previously undiscovered natural phe-
    nomenon. Id. The patent further states that “[i]t was
    found upon inspection of the sequence alignment that
    there were eleven sites . . . at which the nucleotide ob-
    served for Mycobacterium tuberculosis (MTB) differed
    from all or most related organisms.” Id. col. 12 ll. 18–23.
    Because these signature nucleotides are naturally occur-
    ring, we conclude that the method claims, as informed by
    16               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    the written description, are directed to a patent-ineligible
    natural phenomenon. We turn to Alice/Mayo step two.
    We hold that the method claims do not contain an in-
    ventive concept that transforms the eleven position-
    specific signature nucleotides of the MTB rpoB gene into
    patent-eligible subject matter. PCR amplification of DNA
    is the main action step of the method claims. ’723 patent
    col. 25 l. 60–col. 26 l. 67. The district court found, and
    Roche does not challenge, that “the background tech-
    niques of PCR amplification and detection were ‘routine’
    when the patent application was filed in 1994.” Roche,
    
    2017 WL 6311568
    , at *16 (emphasis added); Appellant Br.
    45 (“In the case at bar, the technique of PCR was well
    known in the prior art.”). Indeed, the ’723 patent itself
    makes clear that “[t]he methods of the present invention
    use standard PCR techniques.” ’723 patent col. 3 ll. 65–66
    (emphasis added). Neither the claims nor the written
    description of the ’723 patent disclose any “new and
    useful” improvement to PCR protocols or DNA amplifica-
    tion techniques in general. The detecting step of claim 1
    is similarly devoid of an inventive concept because it
    involves a simple mental determination of the presence of
    MTB based on the presence or absence of a PCR amplifi-
    cation product.
    Roche asserts that the method claims constitute more
    than a patent-ineligible natural phenomenon. Roche
    argues that at the time of the invention, it was “not
    routine or conventional to use PCR (or any other genetic
    test) to detect the presence of MTB in a biological sample”
    and “unprecedented to perform PCR using the type of
    primer specified in claims 1 through 13.” Roche, 
    2017 WL 6311568
    , at *15; Appellant Br. 42.
    While it may be true that Roche inventors were the
    first to use PCR to detect MTB in a biological sample,
    being the first to discover a previously unknown naturally
    occurring phenomenon or a law of nature alone is not
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID              17
    enough to confer patent eligibility. Many groundbreak-
    ing, innovative, and brilliant discoveries have been held
    patent-ineligible. See e.g., Mayo, 
    566 U.S. at
    73–77 (dis-
    covery of natural correlation between level of certain
    metabolites and drug dosage, resulting in claimed method
    of optimizing treatment using standard techniques to
    administer the drug and then check if the metabolite level
    indicated the need for a dosage change); Genetic Techs.,
    818 F.3d at 1374 (discovery of natural correlation between
    non-coding regions of DNA and the presence of an allele
    in the coding region, resulting in claimed method of
    detecting alleles using standard PCR to amplify and
    detect); Ariosa, 788 F.3d at 1373 (discovery of natural
    phenomenon that pregnant women’s blood contains
    cffDNA, resulting in claimed methods using standard
    techniques to amplify and detect cffDNA in maternal
    blood). The Supreme Court in “Mayo made clear that
    transformation into a patent-eligible application requires
    more than simply stat[ing] the law of nature while adding
    the words ‘apply it.’” Ariosa, 788 F.3d at 1377 (internal
    quotation marks omitted) (quoting Mayo, 
    566 U.S. at 72
    ).
    Alice/Mayo step two’s requirement of “additional features
    that must be new and useful” is simply not met in this
    case because the asserted method claims recite standard
    PCR methods applied to a naturally occurring phenome-
    non; there is no additional innovation. See 
    id.
    Roche argues that to use its primers to detect MTB “is
    no less an inventive act than to make a specific artificial
    drug that is effective to treat an MTB infection.” Appel-
    lant Br. 26 (emphasis omitted). We disagree. It is a well-
    established law of nature that “complementary nucleotide
    sequences bind to each other.” BRCA1, 774 F.3d at 761.
    Roche’s method claims exploit the same law of nature—
    the primer binds to its complementary nucleotide se-
    quence on the MTB rpoB gene. This court’s holding in
    BRCA1 applies to this case with equal force: the primers
    “do not perform a significantly new function. Rather,
    18               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    [they are] used to form the first step in a [PCR] chain
    reaction—a function that is performed because the primer
    maintains the exact same nucleotide sequence as the
    relevant portion of the naturally occurring sequence.” Id.
    Thus, unlike a method of treating a disease with a new
    drug, Roche’s method claims do not involve “a significant-
    ly new function” for the primers. 6 Id.
    This case is distinguishable from CellzDirect, where
    this court vacated a district court’s decision that the
    method claims at issue were ineligible for patenting. 827
    F.3d at 1052. This court held that while the claims were
    based on the discovery of a natural phenomenon (the
    ability of certain liver cells, or hepatocytes, to survive
    multiple freeze cycles), they were “directed to a new and
    useful laboratory technique for preserving hepatocytes”—
    namely, freezing and thawing hepatocytes twice even
    though the prior art taught away from this process. Id. at
    1046–51 (emphasis added) (distinguishing cases that did
    not invent a new and useful method based on the discov-
    ery of a natural phenomenon). This court held that “[t]his
    type of constructive process, carried out by an artisan to
    achieve ‘a new and useful end,’ is precisely the type of
    6   DNA or RNA can sometimes be used as a drug.
    For example, technologies such as RNA interference
    (“RNAi”) and small inhibitory RNAs (“siRNAs”) use RNA
    to silence the expression of individual genes. See, e.g.,
    Univ. of Utah v. Max-Planck-Gesellschaft Zur Forderung
    Der Wissenschaften E.V., 
    734 F.3d 1315
    , 1318 (Fed. Cir.
    2013) (an attorneys’ fees case not involving subject matter
    eligibility of the claims); Ex parte Reich, No. 2013-004817,
    
    2016 WL 750325
    , at *1 (P.T.A.B. Feb. 24, 2016); Ex parte
    Khvorova, No. 2012-010359, 
    2015 WL 4267897
    , at *1
    (P.T.A.B. July 10, 2015). We express no opinion on sub-
    ject matter eligibility of method claims that exploit DNA
    or RNA for drug-like new applications.
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID              19
    claim that is eligible for patenting. . . . [The inventors]
    employed their natural discovery to create a new and
    improved way of preserving hepatocyte cells for later use.”
    
    Id. at 1048
     (emphasis added) (quoting Alice, 
    134 S.Ct. at 2354
    ). Unlike the method claims of the ’723 patent, the
    invention in CellzDirect went beyond applying a known
    laboratory technique to a newly discovered natural phe-
    nomenon, and instead created an entirely new laboratory
    technique that “is not simply an observation or detection”
    based on the natural phenomenon. 
    Id.
     (emphasis added).
    In contrast, the ’723 patent claims a method of detection
    based on a natural phenomenon and employs only con-
    ventional, well-known laboratory techniques, which are
    the opposite of those at issue in CellzDirect. 7
    7    Similarly, this case is also distinguishable from
    Vanda Pharmaceuticals Inc. v. West-Ward Pharmaceuti-
    cals International Ltd., where this court found that the
    claimed methods of treatment are subject matter eligible
    because they claim “‘a new way of using an existing drug’
    that is safer for patients” with schizophrenia at Al-
    ice/Mayo step one. 
    887 F.3d 1117
    , 1135 (Fed. Cir. 2018)
    (quoting Mayo, 
    566 U.S. at 87
    ). But see id. at 1142 (Prost,
    C.J., dissenting) (stating that the treatment claims are
    “no more than an optimization of an existing treatment of
    schizophrenia, just as the claims in Mayo”). Vanda “un-
    derscore[s] the distinction between method of treatment
    claims and those in Mayo,” i.e., claims “directed to a
    diagnostic method.” Id. at 1134–35 (majority opinion). In
    contrast, Roche’s method claims, consisting of a standard
    PCR amplification step and a mental determination step,
    are not directed to a method of treatment. Every time an
    investigator practices Roche’s claimed invention—
    detecting the presence or absence of the eleven signature
    nucleotides of MTB rpoB gene in a sample—she is simply
    rediscovering a preexisting natural phenomenon. Unlike
    20                ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    Roche attempts to distinguish its invention from the
    patent-ineligible method claims in BRCA1. In BRCA1,
    this court invalidated claims 7 and 8, which were directed
    to methods of diagnosing genetic mutations of the BRCA1
    gene in patients, as subject matter ineligible. 8 774 F.3d
    at 763–65. Relevant here, BRCA1 distinguished the
    subject matter ineligible method claims 7 and 8 from the
    potential subject matter eligibility of a different method
    claim, claim 21, which was not asserted and was thus not
    at issue; in dicta, the court pointed out that claim 21
    claims a method of detecting alterations in which
    the alterations being detected are expressly iden-
    tified in the specification by tables 11 and 12.
    These tables expressly identify ten predisposing
    mutations of the BRCA1 gene sequence discovered
    by the patentees. Thus, the detection in claim 21
    is limited to the particular mutations the inven-
    tors discovered: detecting ten specific mutations
    from the wild-type, identified as “[p]redisposing
    [m]utations,” for the specific purpose of identify-
    ing increased susceptibility to specific cancers.
    Claims 7 and 8 are significantly broader and more
    abstract, as they claim all comparisons between
    the patient’s BRCA genes and the wild-type BRCA
    genes.
    Id. at 765 (footnote and citations omitted).
    in Vanda, Roche does not claim a method of treatment
    based on an underlying natural phenomenon, but the
    natural phenomenon itself. Id. at 1135.
    8   Briefly, claim 7 requires “1) hybridizing a BRCA
    gene probe and 2) detecting the presence of a hybridiza-
    tion product. Similarly, claim 8 requires 1) amplification
    of the BRCA1 gene and 2) sequencing of the amplified
    nucleic acids.” BRCA1, 774 F.3d at 764.
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID              21
    Roche argues that its method claims are analogous to
    claim 21, and distinguishable from claims 7 and 8 in
    BRCA1, because they require primers hybridizing to one
    of eleven signature nucleotides expressly identified in the
    claims, and thus would not preempt or limit use of other
    DNAs for detecting MTB. Appellant Br. 34, 50; see ’723
    patent col. 26 ll. 58–68. To be clear, BRCA1 did not find
    claim 21 subject matter eligible; in response to the par-
    ties’ arguments, this court emphasized that “we express
    no view” on whether claim 21 is subject matter eligible,
    and simply noted that “claim 21 is qualitatively different
    from” claims 7 and 8. 774 F.3d at 765. Roche is mistaken
    that limiting the scope of an otherwise ineligible method
    claim would necessarily confer subject matter eligibility.
    Roche’s attempt to limit the breadth of the method claims
    by showing alternative uses of MTB DNA outside of the
    scope of the claims “does not change the conclusion that
    the claims are directed to patent ineligible subject mat-
    ter.” See Ariosa, 788 F.3d at 1379. “While preemption
    may signal patent ineligible subject matter, the absence of
    complete preemption does not demonstrate patent eligibil-
    ity.” Id. Thus, the method claims before us cannot gain
    subject matter eligibility solely because they are limited
    to specific signature nucleotides.
    Therefore, we hold that the asserted method claims of
    the ’723 patent are patent-ineligible because they are
    directed to a natural phenomenon and lack any inventive
    concept that transforms them into patent-eligible subject
    matter.
    IV. CONCLUSION
    For the foregoing reasons, we affirm the district
    court’s summary judgment ruling.
    AFFIRMED
    COSTS
    No costs.
    United States Court of Appeals
    for the Federal Circuit
    ______________________
    ROCHE MOLECULAR SYSTEMS, INC.,
    Plaintiff-Appellant
    v.
    CEPHEID,
    Defendant-Appellee
    ______________________
    2017-1690
    ______________________
    Appeal from the United States District Court for the
    Northern District of California in No. 3:14-cv-03228-EDL,
    Magistrate Judge Elizabeth D. Laporte.
    ______________________
    O’MALLEY, Circuit Judge, concurring.
    I agree with the majority that our decision in In re
    BRCA1- & BRCA2-Based Hereditary Cancer Test Patent
    Litigation, 
    774 F.3d 755
    , 758 (Fed. Cir. 2014) (“BRCA1”)
    compels the conclusion that the primer and method
    claims of 
    U.S. Patent No. 5,643,723
     (“the ’723 patent”) are
    not eligible for patent protection.
    I write separately to express my belief that we should
    revisit our holding in BRCA1 at least with respect to the
    primer claims. Specifically, I believe that our holding
    there was unduly broad for two reasons: (1) the question
    raised in BRCA1 was narrower than our holding in that
    case; and, (2) our interpretation of the nature and func-
    2                 ROCHE MOLECULAR SYSTEMS, INC.      v. CEPHEID
    tion of DNA primers lacked the benefit of certain argu-
    ments and evidence that the patent owner presents in
    this case.
    First, the question before us in BRCA1 was not
    whether the primer claims were patent-ineligible, but,
    rather, whether the district court abused its discretion
    when it denied the patent owner’s motion for a prelimi-
    nary injunction. 774 F.3d at 757. After filing an in-
    fringement suit in district court, the patent owner in
    BRCA1 moved for a preliminary injunction arguing that it
    was likely to succeed on the merits of its infringement
    claim. In re BRCA1-, BRCA2-Based Hereditary Cancer
    Test Patent Litig., 
    3 F. Supp. 3d 1213
    , 1256 (D. Utah
    2014). The district court denied the motion, in part,
    because it found that the accused infringer had “raised a
    substantial question concerning whether [the patent
    owner]’s [p]rimer [c]laims are drawn to patent ineligible
    subject matter.” 
    Id. at 1263
    . The district court made no
    findings regarding whether the primer claims were indeed
    patent ineligible. 
    Id.
     It correctly acknowledged that, “[a]t
    this early stage, . . . the court ‘does not resolve the validity
    question,’ but instead assesses ‘the persuasiveness of the
    challenger’s evidence, recognizing that it is doing so
    without all the evidence that may come out at trial.’” 
    Id. at 1257
     (quoting Titan Tire Corp. v. Case New Holland,
    Inc., 
    566 F.3d 1372
    , 1377 (Fed. Cir. 2009)).
    The patent owner appealed. We affirmed by expressly
    concluding that the primer claims were directed to patent-
    ineligible subject matter. 774 F.3d at 757 (“Because we
    hold that these claims are directed to ineligible subject
    matter under 
    35 U.S.C. § 101
    , we affirm and remand.”);
    
    id. at 761
     (“Primers . . . are patent ineligible”). But that
    was not the question before us; it was only whether the
    district court abused its discretion when it found that the
    accused infringer raised a substantial question regarding
    invalidity under § 101. Appellants’ Br., BRCA1, 
    2014 WL 1668324
    , Nos. 14-1361, -1366 (Fed. Cir. Apr. 18, 2014), at
    ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID                  3
    *2 (listing in its “Statement of Issues” the question of
    “[w]hether the district court erred in finding that Ambry
    raised a substantial question that Myriad’s pair of primer
    claims are not directed to patent eligible subject mat-
    ter . . . .”).
    This procedural context in BRCA1 is important. We
    have routinely recognized that the question of whether an
    accused infringer has raised a substantial question of
    invalidity in the context of a motion for a preliminary
    injunction—such as the question before the district court
    in BRCA1—presents a different type of inquiry than the
    question of whether an asserted claim is invalid—such as
    the question that was before the district court on sum-
    mary judgment in this case. Indeed, “[w]hile the eviden-
    tiary burdens at the preliminary injunction stage track
    the burdens at trial, importantly the ultimate question
    before the trial court is different” because “[i]nstead of the
    alleged infringer having to persuade the trial court that
    the patent is invalid, at [the preliminary injunction]
    stage[,] it is the patentee, the movant, who must persuade
    the court that, despite the challenge presented to validity,
    the patentee nevertheless is likely to succeed at trial on
    the validity issue.” Titan Tire, 
    566 F.3d at 1377
    . Signifi-
    cantly, “the trial court ‘does not resolve the validity ques-
    tion, but rather must . . . make an assessment of the
    persuasiveness of the challenger’s evidence, recognizing
    that it is doing so without all of the evidence that may
    come out at trial.” 
    Id.
     (emphasis added) (citations omit-
    ted).
    This brings me to my second point. Because of the
    procedural posture in BRCA1, it is hardly surprising that
    we did not have the benefit of certain arguments and
    evidence that the patent owner presents in this case when
    we decided BRCA1. As noted, in BRCA1, we considered
    whether claims directed to the following were patent-
    eligible under § 101:
    4                ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    A pair of single-stranded DNA primers for deter-
    mination of a nucleotide sequence of a BRCA1
    gene by a polymerase chain reaction, the sequence
    of said primers being derived from human chro-
    mosome 17q, wherein the use of said primers in a
    polymerase chain reaction results in the synthesis
    of DNA having all or part of the sequence of the
    BRCA1 gene.
    774 F.3d at 759 (quoting 
    U.S. Patent No. 5,747,282
     col.
    155, ll. 23–29). In concluding that these claims were not
    eligible for patent protection, we relied primarily on the
    Supreme Court’s decision in Ass’n for Molecular Pathology
    v. Myriad Genetics, Inc., 
    569 U.S. 576
     (2013), which
    involved other claims related to the BRCA1 gene. See
    BRCA1, 774 F.3d at 759–61.
    In Myriad, the Supreme Court separately considered
    the eligibility of claims directed to “isolated DNA” having
    a specific genetic sequence, on the one hand, and those
    directed to complementary DNA (“cDNA”)—synthetically
    created DNA “which contains the same protein-coding
    information found in a segment of natural DNA but omits
    portions within the DNA segment that do not code for
    proteins”—on the other. 569 U.S. at 580. The Court
    began its analysis by observing that the patent owner in
    Myriad “did not create or alter any of the genetic infor-
    mation encoded in the BRCA1 and BRCA2 genes,” nor did
    it “create or alter the genetic structure of DNA.” 569 U.S.
    at 590. “Instead, [the patent owner]’s principal contribu-
    tion was uncovering the precise location and genetic
    sequence of the BRCA1 and BRCA2 genes within chromo-
    somes 17 and 13.” Id. The Court concluded that, in light
    of this “principal contribution,” the isolated DNA claims
    were not eligible for patent protection, while the cDNA
    claims, which do not occur in nature, were. Id. at 593–94.
    The Court distinguished the isolated DNA claims
    from the “modified bacterium” claims held patent-eligible
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID                5
    in Diamond v. Chakrabarty, 
    447 U.S. 303
     (1980). 
    Id.
     at
    590–91. In the Court’s view, Chakrabarty’s claims were
    eligible because his bacterium was “new ‘with markedly
    different characteristics from any found in nature.’” 
    Id.
    (quoting Chakrabarty, 
    447 U.S. at 310
    ). The patent
    owner in Myriad, in contrast, “did not create anything”
    when it isolated DNA having a particular sequence—
    though “it found an important and useful gene, . . . sepa-
    rating that gene from its surrounding genetic material is
    not an act of invention.” Id. at 591. Critically, the Court
    recognized that claims are not “saved by the fact that
    isolating DNA from the human genome severs chemical
    bonds and thereby creates a nonnaturally occurring
    molecule”: the “claims are simply not expressed in terms
    of chemical composition, nor do they rely in any way on
    the chemical changes that result from the isolation of a
    particular section of DNA.” Id. at 593. It went on to
    explain that “[i]f the patents depended upon the creation
    of a unique molecule, then a would-be infringer could
    arguably avoid at least Myriad’s patent claims on entire
    genes . . . by isolating a DNA sequence that included both
    the BRCA1 or BRCA2 gene and one additional nucleotide
    pair.” Id.
    The Court reached a different conclusion with respect
    to the patent owner’s cDNA claims. The Court began by
    stating that the “creation of a cDNA sequence from
    mRNA results in an exons-only molecule that is not
    naturally occurring.” Id. at 594. It noted that, although
    viruses can incorporate cDNA into the human genome in
    rare instances, “[t]he possibility that an unusual and rare
    phenomenon might randomly create a molecule similar to
    one created synthetically through human ingenuity does
    not render a composition of matter nonpatentable.” Id. at
    594 n.8 (emphasis omitted). The Court rejected the
    accused infringers’ argument that cDNA is not patent
    eligible because “[t]he nucleotide sequence of cDNA is
    dictated by nature, not by the lab technician,” writing
    6                ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    that “the lab technician unquestionably creates something
    new when cDNA is made.” Id. at 595. This is because,
    while “cDNA retains the naturally occurring exons of
    DNA, . . . it is distinct from the DNA from which it was
    derived” because the intron sequences are removed. Id.
    Thus, the Court concluded that “cDNA is not a ‘product of
    nature’ and is patent eligible under § 101, except insofar
    as very short series of DNA may have no intervening
    introns to remove when creating cDNA.” Id. “In that
    situation, a short strand of cDNA may be indistinguisha-
    ble from natural DNA.” Id.
    In BRCA1, we discussed Myriad’s teachings, culmi-
    nating in a summary of that case by citing the Supreme
    Court’s observation that, “[t]o the extent that the exon-
    only sequence does not exist in nature, the lab technician
    ‘unquestionably creates something new when cDNA is
    made.’” 774 F.3d at 760 (quoting Myriad, 569 U.S. at
    595). But, in the very next sentence, we concluded that
    “[t]he primers before us are not distinguishable from the
    isolated DNA found patent-ineligible in Myriad and are
    not similar to the cDNA found to be patent-eligible.” Id.
    We arrived at this conclusion based on two facts that we
    perceived as entirely resolving the question of whether
    primers are structurally identical to that which exists in
    nature. We found that “[p]rimers necessarily contain the
    identical sequence of the BRCA sequence directly opposite
    to the strand to which they are designed to bind,” and
    that “[t]hey are structurally identical to the ends of DNA
    strands found in nature.” Id.
    But it is not clear from the BRCA1 opinion or record
    why we reached this conclusion. The lack of record evi-
    dence underlying BRCA1’s conclusion on this point is
    important in light of the record in this case. Specifically,
    BRCA1 concludes that primers have “identical sequences”
    to the natural DNA strands directly opposite the strands
    to which they bind, but, as the record in this case reveals,
    a finding that the two have identical sequences does
    ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID                  7
    entirely resolve the question of whether they are struc-
    turally identical because structure is not defined solely by
    nucleotide sequence. 1 Nor is it clear how primers “are
    structurally identical to the ends of DNA strands found in
    nature.” Id. As I explain below, the additional facts in
    this record, viewed in the light most favorable to Roche,
    give rise to genuine issues of material fact 2 regarding
    whether the claimed primers have a “unique structure,
    different from anything found in nature,” and therefore,
    challenge the conclusion that this entire class of mole-
    cules is ineligible under § 101.
    Roche developed a record in this case demonstrating
    the ways in which the claimed primers differ structurally
    from anything that occurs in nature. Roche first submit-
    ted evidence supporting a finding that the claimed pri-
    mers differ from primers that naturally occur in the
    bacteria of the M. tuberculosis complex (“MTB”). Roche’s
    expert explained that, unlike the claimed primers, the
    naturally occurring MTB primers are never single-
    stranded. J.A. 1892 at ¶ 88. Roche’s expert also ex-
    plained that the naturally occurring MTB primers are
    comprised of RNA whereas the claimed primers are
    comprised of DNA. J.A. 1892 at ¶ 89. This means that
    1  Notably, there can be no dispute that primers,
    though complementary, are structurally different in
    sequence from the strands to which they hybridize.
    Indeed, a primer comprising a nucleotide sequence of
    ATCG is complementary to, but unquestionably different
    from, a natural DNA strand comprising a sequence of
    TAGC.
    2  See Berkheimer v. HP Inc., 
    890 F.3d 1369
    , 1370
    (Fed. Cir. 2018) (Moore, J., concurring in the denial of
    rehearing en banc) (“While the ultimate question of
    patent eligibility is one of law, it is not surprising that it
    may contain underlying issues of fact.”).
    8                ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID
    naturally occurring MTB primers differ chemically from
    the claimed primers “both (i) in the type of sugar they
    contain (ribose [in MTB primers] v. deoxyribose [in the
    claimed primers]) and (ii) the sets of bases that they use
    (A, C, G, U [in the MTB primers] v. A, C, G, T [in the
    claimed primers]).” J.A. 1892 at ¶ 89. Finally, Roche’s
    expert explained that “[n]aturally occurring MTB primers
    are 3–10 nucleotides long, and thus differ structurally
    from the claimed primers, which are at least 14 nucleo-
    tides long.” J.A. 1892 at ¶ 90. This record evidence
    supports a finding that the claimed primers differ from
    naturally occurring MTB primers.
    Roche also explained that the claimed primers differ
    structurally from the native MTB rpoB gene. Roche
    explained that because “the DNA of MTB occurs in the
    form a circular chromosome,” the native MTB rpoB gene
    lacks a 3-prime end with a 3-prime hydroxyl (-OH) group.
    J.A. 1891 at ¶ 85. In contrast, the parties agree that the
    claimed primers necessarily have hydroxyl groups at their
    3-prime end, and that skilled artisans would recognize as
    much. Roche’s expert explained that “[a] free hydroxyl
    group at the 3’ end of the primer or extension product is
    essential for DNA replication, because it provides a free
    end to which the next nucleotide can be attached.” J.A.
    1881 ¶ 40 (emphasis added). Indeed, “[a] DNA that lacks
    a free hydroxyl group at the 3’ end cannot support replica-
    tion and thus cannot serve as a primer.” J.A. 1881 ¶ 40;
    see also J.A. 1884–85 ¶ 48 (“If a DNA does not have a free
    hydroxyl at the 3’-end, it cannot be a primer.”).
    Moreover, because the DNA of MTB found in nature
    occurs in the form of a circular chromosome, and therefore
    lacks any sort of end, J.A. 1876 at ¶ 26 (“If the DNA is in
    the form of a closed circle, there are no . . . 3-prime ends,
    nor a 3-prime hydroxyl group.”), the claimed primers
    cannot be “structurally identical to the ends of DNA
    strands found in nature,” as we concluded in BRCA1, 774
    F.3d at 760. And, even if the DNA in MTB occurred in
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID                 9
    linear strands, Roche’s expert testified that, in linear
    strands of native DNA, only the last nucleotide in the
    entire strand typically has a hydroxyl group at its 3-prime
    end. Thus, based on the above evidence, Roche’s expert
    concluded that, while a portion of the native MTB rpoB
    gene has the same nucleotide sequence as the claimed
    primers, the two differ chemically vis-à-vis the presence of
    a 3-prime end with a 3-prime hydroxyl group at a
    nonnaturally occurring location. See J.A. 1892 at ¶ 86
    (“Thus, there is a chemical difference between the primer
    and the longer DNA strand of which the primer has, in
    part, the same sequence.”).
    Said another way, although it is undisputed that all
    the claimed primers here have nucleotide sequences that
    are identical to segments of the naturally occurring rpoB
    gene found in MTB, a genuine factual dispute exists as to
    whether they have a materially different structure than
    any DNA molecules typically found in nature. Cf. Myriad,
    569 U.S. at 595 (deeming relevant whether short strands
    of cDNA are “indistinguishable from natural DNA”);
    Chakrabarty, 
    447 U.S. at 310
     (holding claims patent-
    eligible where “the patentee has produced a new bacte-
    rium with markedly different characteristics from any
    found in nature and one having the potential for signifi-
    cant utility”).
    Not only does the record demonstrate that the claimed
    primers could be structurally different from that which
    exists in nature, but the claims here also appear to be
    distinguishable from the molecule that would result from
    isolating the sequence of the strand directly opposite the
    strand to which the claimed primers hybridize. This is
    critical because, in Myriad, the Court explained that
    claims directed to isolated DNA sequences “are not saved
    by the fact that isolating DNA from the human genome
    severs the chemical bonds that bind gene molecules
    together.” 569 U.S. at 592. But, unlike the claims in
    Myriad, which were neither “expressed in terms of chemi-
    10                ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID
    cal composition, nor” reliant “in any way on the chemical
    changes that result from the isolation of a particular
    section of DNA,” 569 U.S. at 592, the primer claims here,
    by virtue of being directed to the well-known, structural
    term “primer” and by virtue of including “14-50 nucleo-
    tides that hybridize[] under hybridizing conditions” to at
    least one signature nucleotide, ’723 patent, col. 28, ll. 14–
    31, are expressed in terms of chemical composition and
    are reliant on the presence of a 3-prime end and a 3-prime
    hydroxyl group at a nonnaturally occurring location.
    Therefore, Roche’s evidence regarding the presence of a 3-
    prime end with a 3-prime hydroxyl group, coupled with
    the claim language, support a finding that the claims here
    are distinguishable from the DNA claims in Myriad.
    These structural differences between the claimed
    primers and that which exists in nature are not my only
    concerns with our conclusion in BRCA1, however: we also
    held that primers “do not perform a significantly new
    function” than does naturally occurring DNA. 774 F.3d at
    761. In reaching this conclusion, we rejected the patent-
    ee’s contention that DNA, when part of the naturally
    occurring genetic sequence, “stores the biological infor-
    mation used in the development and functioning of all
    known living organisms,” but when isolated as a primer,
    the DNA fragment “prime[s], i.e., . . . serve[s] as a starting
    material for a DNA polymerization process.” Id. We
    disagreed, writing that:
    [i]n fact, the naturally occurring genetic sequences
    at issue here do not perform a significantly new
    function. Rather, the naturally occurring material
    is used to form the first step in a chain reaction—
    a function that is performed because the primer
    maintains the exact same nucleotide sequence as
    the relevant portion of the naturally occurring se-
    quence. One of the primary functions of DNA’s
    structure in nature is that complementary nucleo-
    tide sequences bind to each other. It is this same
    ROCHE MOLECULAR SYSTEMS, INC.    v. CEPHEID                 11
    function that is exploited here—the primer binds
    to its complementary nucleotide sequence. Thus,
    just as in nature, primers utilize the innate ability
    of DNA to bind to itself.
    Id. at 760–61 (emphasis added). We then concluded that
    Myriad does not “confer[] patent eligibility on composition
    of matter claims directed to naturally occurring DNA
    strands under such circumstances.” Id. at 761. Thus, “[a]
    DNA structure with a function similar to that found in
    nature can only be patent eligible as a composition of
    matter if it has a unique structure, different from any-
    thing found in nature.” Id. (citations omitted). We,
    therefore, held that “[p]rimers do not have such a differ-
    ent structure and are patent ineligible.” Id.
    Here, not only is there at least a genuine issue of ma-
    terial fact as to whether the claimed primers have a
    different structure from anything found in nature, the
    record also suggests that the claimed primers may have a
    different function from that of native DNA. Particularly,
    record evidence shows that, unlike native DNA, which
    merely stores genetic information and serves as a tem-
    plate for replication, the claimed primers can selectively
    hybridize, or bind, to specific nucleotides of a target
    gene—here, the “signature nucleotides” of the MTB rpoB
    gene. This function is reliant on the presence of the free
    3-prime hydroxyl group at a nonnaturally occurring
    location and allows scientists, among other things, to
    amplify and detect the MTB rpoB gene using techniques
    such as polymerase chain reaction (“PCR”). The fact that
    claimed primers, once synthesized, “utilize the innate
    ability of DNA to bind to itself,” id. at 761, to achieve this
    selective hybridization should not render them wholesale
    patent-ineligible. In Myriad, the Supreme Court ex-
    plained that, although “[t]he nucleotide sequence of cDNA
    is dictated by nature, not by the lab technician,” this is
    irrelevant for § 101 purposes because “the lab technician
    unquestionably creates something new when cDNA is
    12               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    made.” 569 U.S. at 595. Similarly, this record contains
    evidence that the lab technician creates something new
    when the claimed primers are made, even though, once
    made, the primers “utilize the innate ability of DNA to
    bind to itself.” BRCA1, 774 F.3d at 760–61.
    Cepheid argues on appeal that the patent owner in
    BRCA1 pointed to the same differences that Roche points
    to here. Specifically, Cepheid contends that the patent
    owner in BRCA1 raised the same 3-prime hydroxyl group
    argument that Roche makes here, and that we squarely
    rejected that argument. But, that is not an accurate
    characterization of the record in BRCA1. There, the
    patent owner merely alluded to the structural distinction
    between primers and native DNA when explaining the
    functional differences between the two. Appellants’ Br.,
    In re BRCA1, 
    2014 WL 1668324
    , at *50. The only refer-
    ence the patent owner made to the free 3-prime hydroxyl
    group was in its statement of facts in its opening brief
    where it stated that, “[t]here are no short, single strands
    of DNA with a free 3’-OH group in nature that can serve
    as primers.” 
    Id. at *8
    . Notably, when attempting to
    establish the existence of structural differences between
    native DNA and primers, the patent owner in BRCA1 did
    not reference the presence of a hydroxyl group at a
    nonnaturally occurring location and focused instead on
    the fact that primers are designed and synthetically
    created in a lab. 
    Id.
     at *48–50. Therefore, perhaps be-
    cause of the procedural posture in which the issue was
    developed, the patent owner in BRCA1 did not develop a
    record demonstrating that primers differ structurally
    from native DNA based on the presence of a hydroxyl
    group at a nonnaturally occurring location. Nor did we
    expressly address this hydroxyl group “argument” in
    BRCA1 or include language indicating that we had con-
    sidered, but rejected, any such argument.
    The patent owner in BRCA1 also never argued that
    its claimed primers were structurally distinct from natu-
    ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID               13
    rally occurring primers. While the patent owner in
    BRCA1 pointed out that “[t]here are no short, single
    strands of DNA with a free 3’-OH group in nature that
    can serve as primers” and that “[i]n natural DNA replica-
    tion, RNA primers are used as the starting material,” it
    never used these facts to demonstrate that the primers at
    issue were structurally distinct from anything that exists
    in nature. Appellants’ Br., BRCA1, 
    2014 WL 1668324
    , at
    *8. Simply, the patent owner in BRCA1 did not make the
    specific arguments Roche makes here.
    These points were also not raised or addressed in
    Myriad. While the patent owner there argued that native
    DNA differs from isolated DNA because “[n]ative DNA
    cannot be used as a molecular tool, such as a probe or a
    primer,” it did not explain that isolated DNA differs
    structurally from native DNA vis-à-vis a 3-prime end and
    a 3-prime hydroxyl group at a nonnaturally occurring
    location. Myriad’s Mem. of Law in Support of Mot. for
    Summary J. and in Opp. to Pl’s Mot. for Summary J.,
    Myriad Genetics v. Assoc. for Molecular Pathology, No.
    1:09-cv-04515-RWS (S.D.N.Y. Dec. 23, 2009), ECF No.
    153, 8–9. Significantly, and as explained above, the
    claims at issue in Myriad were not reliant on the presence
    of this 3-prime hydroxyl group at a nonnaturally occur-
    ring location. Accordingly, Myriad could not have proper-
    ly raised, and the Supreme Court could not have
    considered, the particular points that Roche now raises.
    See Myriad, 569 U.S. at 593 (“Myriad’s claims are simply
    not expressed in terms of chemical composition, nor do
    they rely in any way on the chemical changes that result
    from the isolation of a particular section of DNA.”).
    Therefore, unlike the appellants in Myriad and in
    BRCA1, here, Roche submitted evidence of record that, at
    the very least, raises genuine issues of material fact as to
    whether there exists anything in nature that both has the
    structure and performs the function of the claimed pri-
    mers. For these reasons, while I agree with the majority
    14               ROCHE MOLECULAR SYSTEMS, INC.   v. CEPHEID
    that the broad language of our holding in BRCA1 compels
    the conclusion that the primer claims in this case are
    ineligible under 
    35 U.S.C. § 101
    , I believe that holding
    exceeded the confines of the issue raised on appeal and
    was the result of an underdeveloped record in that case. I
    believe, accordingly, that we should revisit our conclusion
    in BRCA1 en banc.