IFNG and cancer: An important immunosuppressive cytokine, transforming growth factor beta (TGFβ), is secreted by many cancers including melanoma, breast and colon cancer and is known to prevent cytotoxic T cell (CTL) expansion and activation (Mooradian et al., 1990), TGFβ and IL-10 are involved in the generation of regulatory T cells (Treg) which in turn inhibit CD8+ T cell activation and IFNγ secretion (Nishikawa et al., 2005).