Since the Supreme Court’s decision in Bilski v. Kappos, the Federal Circuit and district courts have issued numerous—and sometimes conflicting—decisions (e.g., Research Corp. Technologies, Inc., CyberSource, Classen Immunotherapies) on what constitutes patentable subject matter. Anthony Lo Cicero of Amster, Rothstein & Ebenstein LLP analyzes these decisions, seeks to discern a common thread of analysis, and predicts the next Supreme Court decision on the subject in Mayo v. Prometheus.