The latest updates to the heart failure treatment guidelines by the American College of Cardiology recommend the use of sodium-glucose cotransporter 2 (SGLT2) inhibitors, either dapagliflozin and empagliflozin, in patients with heart failure with reduced ejection fraction (HFrEF) irrespective of diabetes status as add-on therapy [1]. This evidence concerns the gene SLC5A2 and diabetes mellitus.