Through blockade of the RAAS via AT1 antagonism with valsartan and inhibition of neprilysin via sacubitril, sacubitril/valsartan has been shown to increase the levels of ANP and BNP (most likely the processed bioactive forms) and to decrease levels of NT-proBNP, with significant improvement in the outcomes of patients with HFrEF observed, including decreases in rates of CV mortality and HF hospitalization. The gene discussed is AGTR1; the disease is hydrops fetalis.