Extracellular dipeptidyl-peptidase which removes N-terminal dipeptides sequentially from polypeptides having unsubstituted N-termini. Contributes to pathogenicity (By similarity). Expression is strongly increased during growth on protein-rich medium containing keratin. Causes an allergic reaction in human. Binds to IgE and associated with delayed type hypersensitivity. Belongs to the peptidase S9C family.