Specifically, in cancer cells carrying C/C genotype treatment with nivolumab dramatically decreased cancer cell survival (Fig. 5A) and increased apoptotic cancer cells (Fig. 5B), PBMC-mediated LDH (Fig. 5C), IFN-γ (Fig. 5D), TNFα (Fig. 5E) releases as well as the percentage of positive CD107a PBMCs (Fig. 5F) as compared to cells treated with isotype control and co-cultured with activated matched PBMCs. Here, IFNG is linked to cancer.