Carboxypeptidases are zinc-containing exopeptidases that catalyze the release of carboxy-terminal amino acids, and are synthesized as zymogens that are activated by proteolytic cleavage. Carboxypeptidases cleave amino acids from the C-terminus of proteins and peptides and many are metalloproteases. Carboxypeptidase A4 (CPA4) is also known as Carboxypeptidase A3 (CPA3), which belongs to the peptidase M14 family. Fetal express the protein in the adrenal gland, brain, heart, intestine, kidney, liver and lung.