Dipeptidyl peptidase 8 is an enzyme that in humans is encoded by the DPP8 gene.

This gene encodes a member of the peptidase S9B family, a small family of dipeptidyl peptidases that are able to cleave peptide substrates at a prolyl bond. The encoded protein shares similarity with dipeptidyl peptidase IV in that it is ubiquitously expressed, and hydrolyzes the same substrates. These similarities suggest that, like dipeptidyl peptidase IV, this protein may play a role in T-cell activation and immune function. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008].
Function: Dipeptidyl peptidase that cleaves off N-terminal dipeptides from proteins having a Pro or Ala residue at position 2. May play a role in T-cell activation and immune function.