Anti-carboxypeptidase O antibodies are used for the immunodetection of the protein encoded by the CPO gene. In humans, the canonical protein has a reported length of 374 amino acid residues and a mass of 42.5 kDa. Its subcellular localization is in the cell membrane. It is notably expressed in enterocytes of the ileum. A member of the Peptidase M14 protein family, it is known to be involved with proteolysis. Post-translational modifications have been described, including N-glycosylation. Other names for this target antigen include metallocarboxypeptidase C and metallocarboxypeptidase O. Gene orthologs have been identified in the mouse, rat, bovine, zebrafish, chimpanzee and chicken species. These carboxypeptidase O antibodies are widely used in Western Blot experiments, among other applications.