These cytotoxic T cells exert their tumor-killing effects through multiple mechanisms, including the release of granule-associated cytokines, induction of necrosis or apoptosis via ligand-receptor interactions, and secretion of pro-inflammatory cytokines such as interferon-γ (IFN-γ) and TNF-α, which mediate direct cytotoxicity against tumor cells (25, 26). This evidence concerns the gene TNF and neoplasm.