Dipeptidyl peptidases (DPPs) mediate regulatory activity of their substrates and have been linked to a variety of diseases including type 2 diabetes, obesity and cancer. DPPs have post-proline dipeptidyl aminopeptidase activity, cleaving Xaa-Pro dipeptides from the N-termini of proteins. DPPs can bind specific voltage-gated potassium channels and alter their expression and biophysical properties and may also influence T cells. DPP proteins include DPRP1, DPRP2, DPP3, DPP7, DPP10, DPPX and CD26. DPP3 (dipeptidyl-peptidase 3), also known as DPPIII, is a zinc-exopeptidase that belongs to the peptidase M49 family. DPP3 localizes to the cytoplasm and is involved in intracellular protein catabolism. More specifically, DPP3 is an important enzyme involved in the degradation of enkephalins. An increase in the activity of DPP3 is implicated in ovarian and endometrial cancers.