The TECOS (Trial Evaluating Cardiovascular Outcomes with Sitagliptin) trial was a landmark cardiovascular outcomes study designed to evaluate the cardiovascular safety of sitagliptin, a widely prescribed dipeptidyl peptidase-4 (DPP-4) inhibitor, in patients with type 2 diabetes who were at risk for cardiovascular events. Here, DPP4 is linked to type 2 diabetes mellitus.