Anti-carboxypeptidase A4 antibodies are used in the immunodetection of the protein encoded by the CPA4 gene. In humans, the canonical protein has a reported length of 421 amino acid residues and a mass of 47.4 kDa. It is known to be a secreted protein. Alternative splicing is reported to yield 2 different isoforms for this protein. A member of the Peptidase M14 protein family, it is a reported metalloprotease that could be involved in the histone hyperacetylation pathway. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include CPA3.