IL-6 deficient mice have been reported to exhibit reduced tumor growth and metastasis, and increased IFN-γ producing CD8 T cells; despite improving tumorigenesis, IL-6-/- mice showed enhanced PD-L1 expression on murine CT26 colon cancer cells which could be mitigated by anti-PD-L1 immunotherapy [60, 61]. The gene discussed is IFNG; the disease is malignant colon neoplasm.