IFNG and neoplasm: Additionally, IFNγ regulates several processes involved in tumor-immune cell interactions, including direct antigen processing and presentation via regulation of MHCI, B2M, TAP, and immunoproteasome components (161–164), as well as feedback inhibition of T cell responses via the expression of the IFN-regulated molecules PD-L1 and PD-L2 in both tumor and immune cells (165, 166).