The US Court of Appeals for the Federal Curcuit in March ruled for Eli Lilly in Indianapolis, Indiana, and against Ariad Pharmaceuticals, affirming an earlier decision by a three-judge panel and dealing a possible death blow to Ariad's broad claims on the nuclear factor κB (NF-κB) pathway (Nat. Biotechnol. 27, 494, 2009). A 2006 jury ruling that Lilly's Evista (raloxifene) and Xigris (activated protein C) infringed Cambridge, Massachusetts–based Ariad's NF-κB patent alarmed much of the drug development world, stoking fears that broad patent claims on biological pathways would stifle drug development. The March opinion again invalidated Ariad's claims and affirmed that patents must meet a written description requirement separate from an enablement requirement—an issue that has divided the appeals court since a 1997 ruling established written description, dubbed the Lilly doctrine (Nat. Biotechnol. 16, 87, 1998). Ariad is considering petitioning for Supreme Court review. But the Supreme Court has “bigger fish to fry with patentable subject matter right now,” says University of Michigan law professor Rebecca Eisenberg, alluding to Association for Molecular Pathology v. US Patent and Trademark Office (the Myriad Genetics gene patenting case, seemingly destined for Supreme Court review), and Prometheus v. Mayo, another dispute over the patentability of 'natural processes'. Ariad also lost an NF-κB patent infringement case against Amgen, of Thousand Oaks, California, and the US Patent and Trademark Office invalidated most of Ariad's patent claims in a separate review (Ariad has appealed), suggesting the NF-κB patent has little life left.