A reinvigoration of anti-tumor immune responses by treating with immune checkpoint inhibitors is strongly accompanied with the increased serum levels of IFN-γ and the IFN-γ-induced chemokines (CXCL-9 and CXCL-10) together with increased numbers of IFN-γ-producing T cells in both peripheral blood and tumor tissues [53]. The gene discussed is CXCL9; the disease is neoplasm.