In a much-watched case, the Supreme Court in MedImmune Inc. v. Genentech Inc., 2007 DJDAR 348 (Jan. 9), recently reversed the U.S. Court of Appeals for the Federal Circuit and held that a federal district court had subject-matter jurisdiction under the Declaratory Judgment Act to hear a suit brought by patent licensee MedImmune against Genentech to establish the patent's invalidity.