A-type (Atrial) natriuretic peptide (ANP), also called Cardiodilatine (CDD), is a peptide hormone composed of 28 amino acids. It is processed from a 151aa prepro-ANP by signal peptide removal, followed by specific protease cleavage by corin of the pro-ANP. The 28a C-terminal peptide hormone contains a 17aa ring formed by a disulfide bridge between Cys7 and Cys23. and a tail. It is produced in cardiac myocytes, where it exerts vasodilating effects, hence playing an important role in the regulation of blood pressure and natriuresis/diuresis. Residues Phe8, Arg14 and the C-terminal sequence of ANP are known to bind to human NPR-A (Natriuretic peptide receptor type A). ANP is closely related to BNP (brain natriuretic peptide) and CNP (C-type natriuretic peptide), which share a similar ring structure.