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. Here, GCG is linked to type 2 diabetes mellitus.