GCG and type 2 diabetes mellitus: Incretin-based therapies have been established for type 2 diabetes and involve the use of GLP-1 analogues to increase GLP-1 receptor agonist concentrations in the pharmacological range and dipeptidyl peptidase-4 (DPP-4) inhibitors to prevent the degradation of endogenous GLP-1 and GIP, which are both substrates for the DPP-4 enzyme, elevating their plasma levels [1].