DPP4 and type 2 diabetes mellitus: The enzyme dipeptidyl peptidase-4 (DPP4) inhibition has emerged as one of the novel targets via specific classical and non-classical mechanisms among the diverse therapeutic aspects of T2DM owing to its ability to degrade incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) [6].