DPP4 and type 2 diabetes mellitus: In general, biguanides (e.g., MET), thiazolidinediones (e.g., rosiglitazone), insulin secretagogues (sulphonylureas such as glimepiride, meglitinides such as repaglinide), α-glucosidase inhibitors (e.g., acarbose), incretin-based therapies (GLP-1 agonists such as dulaglutide, dipeptidyl peptidase 4 (DPP4) inhibitors such as sitagliptin), and SGLT2 inhibitors (e.g., canagliflozin) belong to the common oral antidiabetic medications for T2DM [2,10].