In the meantime, newer GLD classes have become firmly established treatments for T2D, i.e. dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon like peptide-1 receptor agonists (GLP-1 RA) and sodium–glucose cotransporter-2 (SGLT2) inhibitors. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.