Upon antigen recognition, CTLs execute their cytotoxic functions by secreting granzyme B and perforin, increasing the synthesis and release of cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) and inducing tumor cell apoptosis via the FasL/Fas pathway (17, 18). The gene discussed is FAS; the disease is neoplasm.