Moreover, SAgs activated T cells and monocytes also produce various cytolytic cytokines notably IFN-γ, TNF-α, IL-2 which alone or together with nitrous oxide can induce cytotoxicity in both MHCII+ and MHCII- tumor cells (Fast et al., 1991; Dohlsten et al., 1993). This evidence concerns the gene TNF and neoplasm.