Specifically cleaves substrates and peptides with C-terminal basic amino acids, especially those containing C-terminal Arg residues. Probably modulates the Wnt signaling pathway, by cleaving some undefined protein. May play a role in cleavage during prohormone processing. {ECO:0000269|PubMed:11766880, ECO:0000269|PubMed:12417617, ECO:0000269|PubMed:33217972, ECO:0000269|PubMed:9099699}. This is the function of Ensembl gene identifier ENSG00000109625 (CPZ, carboxypeptidase Z).