Conducted in response to regulatory requirements from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for cardiovascular outcomes trials in new diabetes medications, TECOS provided essential insights into the cardiovascular effects of sitagliptin and added to the growing body of evidence on DPP-4 inhibitors in patients with diabetes and established cardiovascular disease [43]. This evidence concerns the gene DPP4 and diabetes mellitus.