IFNG and neoplasm: Both CD8+ cytotoxic T-lymphocytes (CTLs) and CD4+ T-helper cells play important roles in anti-tumor immunity by secreting perforin and granzyme, inducing FasL/TRAIL-mediated cell death, or secreting effector cytokines such as interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) (1–3).