CD26 inhibition in C57BL/6 mice through sitagliptin administration restored lymphocyte-attracting activity of intraperitoneally injected human CXCL10, and of endogenous murine CXCL10 (mCXCL10), resulting in enhanced recruitment of CXCR3+ lymphocytes towards the peritoneal cavity and B16F10 melanoma tumors, respectively [35, 36]. The gene discussed is CXCL10; the disease is melanoma.