IFNγ has an antitumor mechanism targeted by ICIs. It increases tumor immunogenicity, suppresses cancer cell proliferation, increases NK cell cytotoxic functioning, and recruit’s tumor-reactive T cells [37]. Clinic studies have reported increased IFNγ levels following anti-PD-1 ICI therapy and improved prognosis. Further, IFNγ has been shown to be a positive biomarker for successful ICI therapy [37]. This evidence concerns the gene IFNG and neoplasm.