NPR1 and cardiac hypertrophy: The natriuretic peptides ANP and B-type natriuretic peptide (BNP), following co-secretional cleavage to their bioactive peptide hormones, bind and activate the transmembrane guanylyl cyclase receptor, natriuretic peptide receptor A (NPR-A), in the vasculature, kidney, and heart, resulting in intracellular cGMP production that promotes vasodilation, natriuresis, and diuresis and antagonizes cardiac hypertrophy (1,7,9,11,12).