DPP4 and type 2 diabetes mellitus: The receptor targets for T2DM reported by many scientists till date are glycogen phosphorylase, protein tyrosine phosphatase 1-beta (PTP-1β), dipeptidyl peptidase-IV (DPP-IV), glucokinase, peroxisome proliferator activated receptor (PPAR-γ), aldose reductase (AR), insulin receptor (IR), and so forth [13].