According to the ESC 2023 Focus Update of the 2021 ESC Heart Failure Guidelines and the AHA/ACC/HFSA 2022 Guidelines, SGLT2 inhibitors are recommended as Class I for all forms of heart failure: HF with reduced ejection fraction (HFrEF), HF with mildly reduced EF (HFmrEF), and HF with preserved EF (HFpEF) [15,127]. The gene discussed is SLC5A2; the disease is heart failure.