IFNG and neoplasm: IFN-γ displays a dual role in tumor immunology, it promotes immunity via activation of cytotoxic T cells and upregulating expression of MHC-I molecules on tumor cells, but also promotes suppression by inducing expression of PD-1 ligands (Reviewed).[46] Similarly, while IFN-γ upregulates expression of MHC-I and induces expression of MHC-II in fibroblasts7 it promotes expression of PD-L1 and PD-L242 and CD73.