The protein encoded by the DPPIV gene is an antigenic enzyme expressed on the surface of most cell types and is associated with immune regulation, signal transduction and apoptosis. It is an intrinsic membrane glycoprotein and a serine exopeptidase that cleaves X-proline dipeptides from the N-terminus of polypeptides.
DPP? plays a major role in glucose metabolism. It is responsible for the degradation of incretins such as GLP-1.Furthermore it appears to work as a suppressor in the development of cancer and tumours.CD26/DPPIV plays an important role in tumor biology, and is useful as a marker for various cancers, with its levels either on the cell surface or in the serum being increased in some neoplasms and decreased in others.