GLP1R and type 2 diabetes mellitus: Current medications used for T2D focus on improving insulin resistance (metformin, thiazolidinediones), increasing insulin secretion (sulphonylurea) and incretins’ effect (dipeptidyl peptidase 4 inhibitor DPP4-i), increasing glucagon-like peptide-1 receptor agonist (GLP1-RA), and reducing glucose absorption (sodium-glucose cotransporter 2 inhibitors SGLT2-I).