Sacubitril/valsartan, a neprilysin inhibitor and angiotensin II receptor blocker (ARB) combination, was shown to reduce cardiovascular mortality and heart failure (HF) hospitalization by 20% in comparison to enalapril in the PARADIGM-HF trial [1], in different age groups [2], in addition to improving the imbalance between the renin-angiotensin-aldosterone and natriuretic peptide systems [3]. The gene discussed is REN; the disease is hydrops fetalis.