Immunogen sequence: PNTLKPDSYR VTLRPYLTPN DRGLYVFKGS STVRFTCKEA TDVIIIHSKK LNYTLSQGHR VVLRGVGGSQ PPDIDKTELV EPTEYLVVHL KGSLVKDSQY EMDSEFEGEL ADDLAGFYRS EYMEGNVRKV VATTQMQA. CD13, also known as ANPEP, is a 150-170 kDa type II transmembrane zinc-binding ec