In a fractured opinion, the Federal Circuit Court of Appeals, sitting en banc, has established new limits for the non-statutory infringement defense of patent misuse. The Court’s decision in Princo Corp. v. International Trade Commission and U.S. Philips Corp., No. 2007-1386 (Fed. Cir. Aug. 30, 2010) (en banc) limits the patent misuse defense, but preserves it as a potent defense, separate from an antitrust claim. Princo teaches that to avoid triggering the patent misuse defense, license or pooling agreements should not leverage the patentee’s monopoly to restrain competition with respect to a non-patented product or process.