DPP4 and type 2 diabetes mellitus: Though many anti-T2D drugs have emerged in the past decade5,6, traditional anti-T2D agents such as repaglinide, metformin, dipeptidyl peptidase-IV inhibitors, α-glucosidase inhibitors and glucagon-like peptide-1 agonists, and thiazolidinediones are still the most efficacious oral drugs in the first-line monotherapy of T2D.7