The mechanisms by which SGLT2 inhibitors cause the reduction in HF admissions and cardiovascular mortality are as yet unknown, however recently suggested theories include their impact on coronary microvascular function and pleiotropic anti-fibrotic effects.7 Extensive evidence has documented the presence of coronary microvascular dysfunction8, , , –12 and myocardial fibrosis13, –15 in patients with T2D. The gene discussed is SLC5A2; the disease is hydrops fetalis.