Proteolytic enzymes, also called proteases, are key players in a variety of biological processes. Our research focuses on a subset of cell membrane proteases that are important in cardiovascular biology and disease. We have discovered a transmembrane serine protease, corin, from the heart. We have shown that corin activates atrial natriuretic peptide (ANP), a cardiac hormone that regulates blood pressure and cardiac function. In knockout mice, a lack of corin causes salt sensitive hypertension. In humans, CORIN gene variants have been associated with hypertension and heart disease. Most recently, we have discovered a novel local function of corin and ANP in regulating spiral artery remodeling in the pregnant uterus. We have identified CORIN gene mutations in patients with pregnancy-induced hypertension. Currently, we use biochemical tools and mouse models to understand the biology of corin and its role in cardiovascular disease.