The principal substrates of NEP in vivo appear to be enkephalins, atrial natriuretic peptide, tachykinins, bradykinin, endothelins, adrenomedullin, members of the vasoactive intestinal peptide family, glucagon, thymopentin, and, most significantly in pathophysiological terms, the Alzheimer's disease Aβ peptide. The gene discussed is MME; the disease is Alzheimer disease.