Prometheus Laboratories, Inc. (“Prometheus”) appeals from the final judgment of the United States District Court for the Southern District of California granting summary judgment of invalidity of U.S. Patents 6,355,623 (“the ’623 patent”) and 6,680,302 (“the ’302 patent”) under 35 U.S.C. § 101. Prometheus Labs., Inc. v. Mayo Collaborative Servs., No. 04-CV-1200, 2008 WL 878910 (S.D. Cal. Mar. 28, 2008) (“Invalidity Opinion”). Because the district court erred as a matter of law in finding the asserted claims to be drawn to non-statutory subject matter, we reverse.