Dipeptidyl peptidase-4 inhibitors (DPP-4i) and the glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have become widely used in T2DM patients as a novel class of blood glucose–lowering drugs with improved weight loss, low risk for hypoglycemia, and reduction in glycated hemoglobin (Drucker and Nauck, 2006; Ismail-Beigi, 2012; Cefalu et al., 2014). This evidence concerns the gene DPP4 and type 2 diabetes mellitus.