IFN-γ enhances the activity of cytotoxic CD8 T cells, NK cells, Th1 cells, dendritic cells and macrophages; stimulates the expression of the major histocompatibility complex (MHC) class I and II molecules in tumor cells and APCs; promotes differentiation of macrophages towards a pro-inflammatory (M1-like) phenotype; and bridges the innate and adaptive immune responses (3, 12, 13). The gene discussed is IFNG; the disease is neoplasm.