DPP4 and type 2 diabetes mellitus: One widely used therapeutic approach for the control of T2D is through the reduction of glucose levels by inhibition of the dipeptidyl peptidase IV (DPP-IV) enzyme, consequently maintaining the concentration of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), two insulin expression inducers [18,24,25].