dissenting from denial of rehearing en banc.
I write to state my concern for the panel’s departure from the established law of anticipation. The court holds “anticipated” a novel chemical compound (descarbe-thoxyloratidine or DCL), a compound not known to the prior art and that did not previously exist. The Schering inventor discovered it in vivo as a degradation product of loratidine, isolated it, determined its structure, and found its biologic properties. The panel nonetheless holds that this new compound is unpatentable on the ground of “inherent anticipation.”
The law is that a product is “anticipated” if it is not new. Conversely, it is not anticipated if it is new. A new product may of course be unpatentable based on obviousness, but it is not subject to unpa-tentabihty for lack of novelty. No precedent supports the position that a product whose existence was not previously known and is not in the prior art is always unpat-entable on the ground that it existed undiscovered. If the law is to be changed in this direction it must be done en banc.
DISCUSSION
The panel appears to have reached the correct result of no liability for infringe*994ment, but for the wrong reason. According to the briefs, the defendants are doing only what was claimed in the expired lora-tidine patent, not in suit. However, instead of simply ruling that Schering cannot prevent the practice of the expired patent in accordance with its teachings, the panel strains to hold that this newly discovered, previously unknown product cannot be validly patented. That is not the law. I also point out that the issue here is validity, not infringement.
Note the word “discovery” in the patent statute. “The term ‘invention’ means invention or discovery.” 35 U.S.C. § 100(a). It was and is well understood that an inventor may discover something that already existed. That the thing was there, undiscovered, does not render it “inherently anticipated.” The panel’s proposed rule may have particular impact on the discovery of biological products. Does the panel intend that no newly discovered product found in an organism can be patented? Such a ruling does not comport with either the patent statute or the incentive purposes of the patent system.
Precedent concerning “anticipation” has dealt with diverse factual situations, applying the common thread that novel subject matter may or may not be patentable, depending on whether it is also unobvious, while subject matter that is not novel cannot be patented. A newly discovered attribute or property of something that was already known is patentable only as a method-of-use, but does not impart patent-ability to the known product. However, a previously unknown product does not become unpatentable simply because it existed before it was discovered. Precedent deals primarily with application of the law to situations where (1) a single prior art reference teaches all the elements of a product as claimed; in such case, the discovery of a new use or function does not render the product itself patentable; and (2) a single prior art reference does not teach all of the claimed elements; in such case the factual question arises of whether the omitted element is shown elsewhere (in which event the issue is obviousness) or whether the omitted element would have been known to be present in the reference subject matter, in which case the issue is anticipation. For example, in In re Schreiber, 128 F.3d 1473 (Fed.Cir.1997) the applicant sought to patent a conical spout to dispense popped popcorn; the same conical spout was shown in the prior art as an oil dispenser. The product itself was thus held unpatentable as anticipated. In MEHL/Biophile International Corp. v. Milgraum, 192 F.3d 1362 (Fed.Cir.1999) the prior art showed all of the claimed steps of laser irradiation of hair follicles, but did not mention hair removal; the court held that this effect was inherent in the prior art process, and that the same process steps could not be claimed, the court stating that “nothing in the claim limits the method’s reach to human skin.” Id. at 1366. In Titanium Metals Corp. v. Banner, 778 F.2d 775 (Fed.Cir.1985) the court held that the discovery of the property of corrosion resistance of a known alloy did not impart patentability to the known alloy, for the property was inherent in the alloy.
In all applications of the law of anticipation, the initial consideration is whether the thing that is claimed was disclosed in a single prior art reference. When all of the elements of the claim are not shown in the prior art, precedent requires that the missing element was nonetheless known to be present in the subject matter of the reference, and that the claim is directed to the known subject matter. Although the panel now purports to disavow this precedent, such a change of law requires en banc action of the court. See, for example, the precedent represented by and cited in such *995cases as Continental Can Co. USA v. Monsanto Co., 948 F.2d 1264 (Fed.Cir.1991), where the law of “inherency” is applied to subject matter wherein all of the elements of the claim are not shown in the prior art:
To serve as an anticipation when the reference is silent about the asserted inherent characteristic, such gap in the reference may be filled with recourse to extrinsic evidence. Such evidence must make clear that the missing descriptive matter is necessarily present in the thing described in the reference, and that it would be so recognized by persons of ordinary skill....
This modest flexibility in the rale that “anticipation” requires that every element of the claims appear in a single reference accommodates situations where the common knowledge of technologists is not recorded in the reference; that is, where technological facts are known to those in the field of the invention, albeit not known to judges.
Id. at 1269-70. The analytic tool of “in-herency” allows determination of whether subject matter that is not taught in the single reference was nonetheless known in the field of the invention. This was acknowledged in EMI Group North America, Inc. v. Cypress Semiconductor Corp., 268 F.3d 1342 (Fed.Cir.2001):
This requirement, that a person of ordinary skill in the art must recognize that the missing descriptive matter is necessarily present in the reference, may be sensible for claims that recite limitations of structure, compositions of matter, and method steps which could be inherently found in the prior art. Such recognition by one of ordinary skill may be important for establishing that the descriptive matter would inherently exist for every combination of a claim’s limitation.
Id. at 1350-51. The panel now contradicts this body of precedent, stating that it “rejects the contention that inherent anticipation requires recognition in the prior art.” A rejection of precedent requires en banc action, not panel disruption.
No reference shows the claimed descar-bethoxyloratidine, or that a person of ordinary skill would have known that DCL is formed in vivo upon ingestion of lorati-dine. Precedent is directly contrary to the panel’s holding that although no one knew of the existence of DCL, it is unpatentable because it in fact existed.
Whether it is desirable new policy to bar the patentability of products that have not yet been discovered is a result I seriously doubt. The court should speak with one voice on this important question. Thus I must, respectfully, dissent from the court’s refusal to review this case en banc.