It has been known for many years that Stat1 is crucial for Ifn-γ expression and cytotoxicity of antitumoral T lymphocytes in vivo (Fallarino and Gajewski 1999); recent work has also shown that loss of inducible STAT1 activation in lymphocytes is a generalized phenomenon in many human cancers and is associated with a failure of lymphocyte activation (Critchley-Thorne et al. 2009). This evidence concerns the gene IFNG and cancer.