DPP4 and diabetes mellitus: Glucagon-like peptide-1 receptor agonists (GLP-1RAs), including exenatide, liraglutide, tirzepatide, and semaglutide, have become key treatments for type 2 diabetes mellitus (T2DM) and obesity, diseases frequently co-occurring with TNBC.4,5,6,7,8 These incretin mimetics exert their glucose-lowering effects primarily through GLP-1 receptor (GLP-1R) activation but overcome the pharmacokinetic limitation of endogenous GLP-1, which is rapidly degraded by dipeptidyl peptidase 4 (DPP4) with a plasma half-life of approximately 2 minutes.