Among the CTL cytokines, interleukin 2 (IL-2) is important for the proliferation of T lymphocytes31; interferon γ (IFNγ) has anti-viral, anti-tumour, and immunoregulatory properties32–34; while tumour necrosis factor α (TNFα) is a multi-functional pro-inflammatory cytokine that is involved in the regulation of a wide spectrum of biological processes35. This evidence concerns the gene IFNG and neoplasm.