Prost, Circuit Judge.

Appeal from the United States District Court for the District of Delaware in No. 1:18-cv-01434-CFC-JLH, Chief Judge Colm F. Connolly. William L. Mentlik, Lerner, David, Littenberg, Krumholz & Mentlik, LLP, Cranford, NJ, argued for plaintiffs-appellants. Also represented by Russell W. Faegenburg, Stephen F. Roth; Robert Jason Fowler, Christopher Neil Sipes, Ashley Marie Winkler, Covington & Burling LLP, Washington, DC. Jeremy Younkin, Foley Hoag LLP, Boston, MA, argued for defendant-appellee. Also represented by Donald Ross Ware. Before Prost, Chen, and Stoll, Circuit Judges. Prost, Circuit Judge.

ChromaDex, Inc. ("ChromaDex") and the Trustees of Dartmouth College ("Dartmouth") (collectively, "Appellants") appeal the decision of the U.S. District Court for the District of Delaware granting Elysium Health, Inc.'s ("Elysium") motion for summary judgment that the asserted claims of U.S. Patent No. 8,197,807 ("the '807 patent") are directed to unpatentable subject matter under 35 U.S.C. § 101. We affirm.

BACKGROUND

I

The '807 patent is directed to dietary supplements containing isolated nicotinamide riboside ("NR"), a form of vitamin B3 naturally present—in non-isolated form—in cow's milk and other products. See '807 patent col. 27 ll. 42-45. Animal cells convert ingested NR into the coenzyme nicotinamide adenine dinucleotide, or NAD +. NAD + deficiencies can cause diseases in both animals and humans.

The asserted claims are claims 1-3 of the '807 patent. Representative claim 1 recites:

1. A composition comprising isolated nicotinamide riboside in combination with one or more of tryptophan, nicotinic acid, or nicotinamide, wherein said combination is in admixture with a carrier comprising a sugar, starch, cellulose, powdered tragacanth, malt, gelatin, talc, cocoa butter, suppository wax, oil, glycol, polyol, ester, agar, buffering agent, alginic acid, isotonic saline, Ringer's solution, ethyl alcohol, polyester, polycarbonate, or polyanhydride, wherein said composition is formulated for oral administration and increased NAD + biosynthesis upon oral administration.

II

ChromaDex sells, among other products, dietary supplements in the form of pharmaceutical compositions of NR embodying the '807 patent. It licenses the patent from Dartmouth. Appellants sued Elysium, a former ChromaDex customer, for patent infringement in September 2018. The district court construed several claim terms; relevant here, the court construed "isolated [NR]" to mean "[NR] that is separated or substantially free from at least some other components associated with the source of [NR]." J.A. 22.

Elysium moved for summary judgment, arguing that the asserted claims were invalid under 35 U.S.C. § 101, and the district court granted the motion. See ChromaDex, Inc. v. Elysium Health, Inc., 561 F. Supp. 3d 460 (D. Del. 2021). The district court concluded that the claims were directed to a natural phenomenon, namely, "compositions comprising isolated [NR], a naturally occurring vitamin present in cow milk." Id. at 464 (cleaned up). It rejected ChromaDex's argument that the characteristics of isolated NR purportedly different from naturally occurring NR— stability, bioavailability, sufficient purity, and therapeutic efficacy—render the claims patent-eligible, observing that none of those characteristics were part of the claims. Id. at 465. It concluded that "the decision to create an oral formulation of NR after discovering that NR is orally bioavailable is simply applying a patent-ineligible law of nature." Id. at 467.

The district court entered judgment of invalidity, and this appeal followed. We have jurisdiction under 28 U.S.C. § 1295(a)(1).

DISCUSSION

I

We review the district court's grant of summary judgment under the law of the regional circuit, here the Third Circuit, which reviews such issues de novo. Junker v. Med. Components, Inc., 25 F.4th 1027, 1032 (Fed. Cir. 2022) (citing Gonzalez v. Sec'y of Dep't of Homeland Sec., 678 F.3d 254, 257 (3d Cir. 2012)). Summary judgment is appropriate when, drawing all reasonable inferences in the nonmoving party's favor, "there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law." Fed. R. Civ. P. 56(a); Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255, 106 S.Ct. 2505, 91 L.Ed.2d 202 (1986). Eligibility under § 101 may involve questions of fact but is, ultimately, a question of law that we review de novo. Nat. Alts. Int'l, Inc. v. Creative Compounds, LLC, 918 F.3d 1338, 1342 (Fed. Cir. 2019); Interval Licensing LLC v. AOL, Inc., 896 F.3d 1335, 1342 (Fed. Cir. 2018).

"Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title." 35 U.S.C. § 101. "Laws of nature, natural phenomena, and abstract ideas," in contrast, "are not patentable." Ass'n for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576, 589, 133 S.Ct. 2107, 186 L.Ed.2d 124 (2013).

II

The parties agree that NR is naturally present in milk. It is undisputed that milk is a naturally occurring product that is not patent eligible. The parties also acknowledge that milk contains tryptophan and lactose, a sugar. And no one disputes that the tryptophan in milk treats NAD + deficiencies. The claims are very broad and read on milk with only one difference as shown:

So the only difference between at least one embodiment within the scope of the claims and natural milk is that the NR in the former is isolated.

The Supreme Court's decisions in Myriad and Diamond v. Chakrabarty, 447 U.S. 303, 309, 100 S.Ct. 2204, 65 L.Ed.2d 144 (1980), apply here. In Chakrabarty, the Court found eligible claims to a genetically engineered bacterium "capable of breaking down multiple components of crude oil." 447 U.S. at 305, 318, 100 S.Ct. 2204. No naturally occurring bacteria possessed the same property. Id. Accordingly, in the Court's view, the "claim [was] not to a hitherto unknown natural phenomenon, but to a nonnaturally occurring manufacture or composition of matter—a product of human ingenuity having a distinctive name, character and use." Id. at 309-10, 100 S.Ct. 2204 (cleaned up). Because "the patentee ha[d] produced a new bacterium with markedly different characteristics from any found in nature and one having the potential for significant utility," the Court upheld the claims. Id. at 310, 100 S.Ct. 2204.

As in Myriad, under the circumstances presented here, the act of isolating the NR compared to how NR naturally exists in milk is not sufficient, on its own, to confer patent eligibility. See Myriad, 569 U.S. at 590-93, 133 S.Ct. 2107. The claimed compositions remain indistinguishable from natural milk because, other than separation from some other components, the isolated NR is no different structurally or functionally from its natural counterpart in milk. Chakrabarty defines the inquiry: to be patentable, the claimed composition must "ha[ve] markedly different characteristics and have the potential for significant utility." 447 U.S. at 310, 100 S.Ct. 2204. Milk, like the claimed compositions, undisputedly "increase[s] NAD + biosynthesis" upon oral administration. The claimed compositions do not exhibit markedly different characteristics from natural milk and are, therefore, invalid for claiming a patent-ineligible product of nature. Cf. Myriad, 569 U.S. at 579, 133 S.Ct. 2107 (concluding "that a naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated" (emphasis added)).

Our Natural Alternatives decision is particularly instructive. There, we upheld, at the motion-to-dismiss stage, claims directed to dietary supplements containing beta-alanine. See 918 F.3d at 1341. We concluded that the patents there claimed "specific treatment formulations that incorporate[d] natural products" and that those formulations "ha[d] different characteristics and c[ould] be used in a manner that beta-alanine as it appears in nature cannot." Id. at 1348. Specifically, the "natural products ha[d] been isolated and then incorporated into a dosage form"—"between about 0.4 grams to 16 grams"—"with particular characteristics"—namely, to "effectively increase[ ] athletic performance." Id. at 1348-49. Those markedly different characteristics distinguished the claimed supplements from natural beta-alanine and preserved the claims' validity. Id. at 1349.

Here, in contrast, the asserted claims do not have characteristics markedly different from milk. Both the claimed compositions and milk "increase[ ] NAD + biosynthesis upon oral administration." Appellants argue that the claimed compositions are advantageous over milk because the isolation of NR allows for significantly more NAD + biosynthesis than is found in milk and that the large quantity of NR itself can alone increase NAD + biosynthesis. But the asserted claims do not require any minimum quantity of isolated NR. Nor do these claims attribute the claimed increase in NAD + biosynthesis to the isolated NR, requiring only that the composition increase NAD + production. Because milk increases NAD + biosynthesis, the claimed compositions do not possess characteristics markedly different from those found in nature. To be sure, the claims cover several different composition embodiments, some of which are structurally different from milk. However, as noted above, the claims also encompass—as both parties agree—at least one embodiment that covers milk, except that the NR element is "isolated." Because the claims are broad enough to encompass a product of nature, it is invalid under § 101.

Appellants nonetheless argue that the claims, in fact, possess markedly different characteristics that render them patent-eligible. See Appellants' Br. 28-31. They base this argument on two main points: (1) "NR is found in milk in only trace amounts," i.e., one part per million; and (2) "what little NR is found in milk is not bioavailable" because it is bound to the lactalbumin whey protein. Id. at 29. The problem for Appellants is two-fold. First, as discussed above, milk increases NAD + biosynthesis (albeit because it contains tryptophan rather than because of the trace amounts of NR), and that is the only therapeutic effect that the claims require. Second, the claims simply do not reflect the distinctions Appellants rely on: they do not require any specific quantity of isolated NR, and the district court's construction for "isolated [NR]," which Appellants do not challenge on appeal, does not require that the NR be separated from the lactalbumin whey protein but only from "some of the other components associated with the source of [NR]." J.A. 22 (emphasis added). The claims, therefore, do not necessarily require that the isolated NR be bioavailable, meaning that the claimed compositions do not necessarily possess markedly different characteristics from milk, as they must to be patent-eligible.

We conclude that the asserted claims lack markedly different characteristics from milk. They claim a product of nature and are not patent eligible.

III

The inquiry could end here—the Supreme Court in Myriad relied on Chakrabarty's "markedly different characteristics" framework for analyzing whether the claimed compositions there were directed to a natural phenomenon; the Court never applied the Alice/Mayo two-step framework despite deciding the case after Mayo. See Myriad, 569 U.S. at 593-95, 133 S.Ct. 2107; see also Alice Corp. Pty. Ltd. v. CLS Bank Int'l, 573 U.S. 208, 217, 134 S.Ct. 2347, 189 L.Ed.2d 296 (2014); Mayo Collaborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66, 77-80, 132 S.Ct. 1289, 182 L.Ed.2d 321 (2012). But if resort to Alice/Mayo is necessary, then at step one we conclude the asserted claims are directed to a product of nature for the reasons stated above, and at step two the claims lack an inventive step because they are directed to nothing more than compositions that increase NAD + biosynthesis, which is the very natural principle that renders the claims patent-ineligible.

Appellants identify only two possible inventive steps: "[1] recognizing the utility of NR for enhancing health and well-being and [2] the wisdom of isolating the NR to provide concentrations higher than what occur naturally." Appellants' Br. 31 (emphasis original). But recognizing the utility of NR is nothing more than recognizing a natural phenomenon, which is not inventive. See Myriad, 569 U.S. at 591, 133 S.Ct. 2107. And the act of isolating the NR by itself, no matter how difficult or brilliant it may have been (although the specification makes clear that it was conventional), similarly does not turn an otherwise patent-ineligible product of nature into a patentable invention. See id. So the claims would likewise fail at step two.

CONCLUSION

We have considered Appellants' remaining arguments and find them unpersuasive. As Appellants conceded at oral argument, our resolution of the patent-eligibility issue moots the standing question. For the reasons set forth above, we affirm the district court's judgment that the asserted claims of the '807 patent are invalid under 35 U.S.C. § 101.

AFFIRMED