ANPEP gene encodes aminopeptidase N (APN) also known as microsomal aminopeptiase, alanyl aminopeptidase, aminopeptidase M, CD13, or membrane protein p161, is a member of the peptidase M1 family. Widely expressed in many cells, tissues and species, APN cleaves the N-terminal amino acids from bioactive peptides, leading to their inactivation or degradation. Probably plays a role in regulating growth and differentiation of early B-lineage cells. It also may play a role in the catabolic pathway of the renin-angiotensin system. It degrades vasoconstricting angiotensin II into angiotensin III and therefore helps to regulate blood pressure.