Carboxypeptidases cleave amino acids from the C-terminus of proteins and peptides and many are metalloproteases. They have distinct expression patterns and different specificities for example, preferentially cleaving aromatic (carboxypeptidase As) or basic (carboxypeptidase Bs) residues. Several, such as carboxypeptidase Xs, have lost their catalytic activity. Carboxypeptidases play important roles in digestion of food, processing of bioactive peptides and blood coagulation.