Background：CD13 is also named as APN, ANPEP(aminopeptidase N), PEPN and belongs to the peptidase M1 family. It is a 150-kD cell surface glycoprotein originally identified on subsets of normal and malignant human myeloid cells.CD13 is an important regulator of angiogenesis where its expression on activated blood vessels is induced by angiogenic signals.
