dissenting from the denial of rehearing en banc.
I respectfully dissent from the court’s decision not to resolve en banc the burgeoning conflict in pronouncements of this court concerning the written description and enablement requirements of the Patent Act. This question has been promoted from simple semantics into a fundamental conflict concerning patent scope and the support needed to claim biological products. The appropriate forum is now the en banc tribunal, not continuing debate in panel opinions applying divergent law.
I fully share Judge Lourie’s understanding of the law. The continuing attack on well-established and heretofore unchallenged decisions such as Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563 (Fed.Cir.1991) (“we hereby reaffirm, that 35 U.S.C. § 112, first paragraph, requires a ‘written description of the invention’ which is separate and distinct from the enablement requirement”) and earlier cases such as In re Ruschig, 54 C.C.P.A. 1551, 379 F.2d 990 (CCPA 1967) (written description is one of three distinct requirements under 35 U.S.C. § 112) is not only unwarranted, but is disruptive of the stability with which this court is charged. If precedent has become obsolete or inapplicable, we should resolve the matter as a court and again speak with one voice.
The new biology has indeed raised new and important questions, with implications for policy as well as law. However, the answer is not the simplistic one espoused by some commentators; it is simply incorrect to say that there is not now and never has been a “written description” requirement in the patent law. It has always been necessary to disclose and describe what is patented. It has never been the law that one can claim what is not made known and set forth in the patent.
Various past decisions have been offered to support the exotic proposition that it is not necessary for the inventor to describe the patented invention, but that enablement alone suffices under the statute. These cases concern traditional issues of generic disclosures and specific examples, and questions of support and predictability for scientific concepts and their embodiments. Such traditional law was applied in Regents of the University of California v. Eli Lilly & Co. 119 F.3d 1559 (Fed.Cir.1997), a case that is misdescribed in this debate, for Lilly does not depart from precedent in its holding that the written description requirement can be fulfilled by “a precise definition, such as by structure, formula, chemical name, or physical properties.” Id. at 1565, quoting Fiers v. Revel, 984 F.2d 1164, 1171 (Fed.Cir.1993).
If the nature of the subject matter is not amenable to precise description, some alternative mode of disclosure is required, such as deposit in a public depository. Enzo Biochem, Inc. v. Gen-Probe, Inc., 323 F.3d 956 (Fed.Cir.2002). However, the public purpose of patents is seriously disserved by eliminating the description requirement entirely. Federal Circuit law *1305of written description has become encumbered with inconsistent pronouncements, leading me to remark that “[cjlaims to an invention that is not described in the specification are an anachronism.” Housey Pharms., Inc. v. Astrazeneca UK Ltd., 366 F.3d 1348, 1357 (Fed.Cir.2004) (Newman, J., dissenting). If the majority of this court is nonetheless sympathetic to that position, there should be careful consideration of the implications of precedent,, for the law is that “Section 112 requires that the application describe, enable, and set forth the best mode of carrying out the invention.” Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 724, 122 S.Ct. 1831, 152 L.Ed.2d 944 (2002).
The issue of whether patent law contains a separate written description requirement has percolated through various panels of this court, on a variety of facts. The differences of opinion among the judges of the Federal Circuit, are, in microcosm, the “percolation” that scholars feared would be lost by a national court at the circuit level. Percolation is the great justifier of conflict among the regional circuits. In the words of the Supreme Court:
We have in many instances recognized that when frontier legal problems are presented, periods of “percolation” in, and diverse opinions from, state and federal appellate courts may yield a better informed and more enduring final pronouncement by this Court.
Arizona v. Evans, 514 U.S. 1, 24 n. 1, 115 S.Ct. 1185, 131 L.Ed.2d 34 (1995). This question has percolated enough; it is ripe for en banc resolution. .