The development of dipeptidyl peptidase-IV (DPP-4) inhibitors, such as vildagliptin, has led to the improvement in glycaemic control in T2D by preventing the degradation of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide. The gene discussed is DPP4; the disease is type 2 diabetes mellitus.