Dipeptidyl peptidase 3(DPP3), is a member of the S9B family in clan SC of the serine proteases. DPP3 has post-proline dipeptidyl aminopeptidase activity, cleaving Xaa-Pro dipeptides from the N-termini of proteins. This cytoplasmic protein binds a single zinc ion with its zinc-binding motif (HELLGH). It releases an N-terminal dipeptide from a peptide comprising four or more residues, with broad specificity and also acts on dipeptidyl 2-naphthylamides.Increased activity of this protein has a relationship with endometrial and ovarian cancers.