RCT: randomized controlled trial, SGLT2: sodium-glucose cotransporter 2, T2DM: type 2 diabetes mellitus, DPP4: dipeptidyl peptidase-4, CHD: congestive heart disease, DAPA: dapagliflozin, PIO: pioglitazone, BEXA: bexagliflozin, ERTU: ertugliflozin, FPG: fasting plasma glucose, SAXA: saxagliptin, EMPA: empagliflozin, SBP: systolic blood pressure, GLP-1 RA: glucagon-like peptide-1 receptor agonist, HbA1c: hemoglobin A1C, BMI: body mass index. This evidence concerns the gene DPP4 and type 2 diabetes mellitus.