Table 2: Possible enzymatic substrates of DPP-4.

Regulatory peptidesBrain natriuretic peptide, GIP, gastrin-releasing peptide (GRP), GLP1, GLP2, GRH, pituitary adenylate-cyclase-activating polypeptide (PACAP)-(1–38), vasoactive intestinal peptide (VIP)

ChemokinesEotaxin (CCL11), IP10 (CXCL10), I-TAC (CXCL11), macrophage-derived chemokine (MDC, CCL22), monokine induced by gamma-interferon (CXCL9), RANTES (CCL5), stromal cell-derived factor-1 (CXCL12), monocyte chemotactic protein-2, granulocyte chemotactic protein-2

NeuropeptidesNPY(1–36), substance P, PYY(1–36), bradykinin, endomorphin-2

OthersGranulocyte macrophage-colony stimulating factor (GM-CSF)
G-CSF, erythropoietin, Interleukin-3, fibroblast growth factor-2, thrombopoietin

IP, interferon-γ-inducible protein; I-TAC, Interferon-inducible T cell a chemoattractant; RANTES, regulated on activation normal T cell expressed and secreted.