I. INTRODUCTION In Amgen Inc. v. Hoechst Marion Roussel, Inc. (Amgen V), (1) the Court of Appeals for the Federal Circuit was once again faced with the difficult question of the proper standard of review in claim construction appeals. The case went back and forth between the district court and the Federal Circuit multiple times before eventually narrowing on the construction of a single claim term. Ultimately, a petition for rehearing en banc was filed arguing that the Federal Circuit panel should have afforded more deference to the district court's claim construction. The petition was denied, but a number of dissenting and concurring opinions underscored the conflict among the Federal Circuit judges. Subsequently, a petition for a writ of certiorari was filed. (2)
