The Patent Act seeks to encourage innovation by protecting new and useful inventions. However, many inventions build on or combine previously known elements, requiring the Patent Office and courts to determine which combinations of, or improvement on, previously known elements are entitled to protection. In doing so, whether or not the claimed invention is patentable often involves asking whether the invention provides unexpected results. We report here on the Federal Circuit's recent decision in In re Couvaras, No. 2022-1489, 2023 WL 3984753 (Fed. Cir. June 14, 2023), which addresses whether finding a purportedly unknown mechanism of action constitutes unexpected results supporting patent protection.