SLC5A2 and hydrops fetalis: However, as alluded to above, ET-1 also plays a role in sodium and water homeostasis, and ET-1 levels correlate with markers of congestion in patients with HF.5,40,41 These findings, along with the fact that ET-1 acts in the proximal renal tubule and experimental evidence that SGLT-2 inhibition reduces ET-1 expression in human proximal tubular cell lines, raised the possibility of an interaction between ET-1 level and the effects of dapagliflozin in patients with HFrEF.21 However, we did not find evidence for this in DAPA-HF.