CD4 T cells can differentiate into various Th subpopulations, which can induce and maintain immune responses against tumor antigens, such as Th1, Th2, regulatory T cells (Tregs), and Th17 etc. Th1 subset that produces interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) and interleukine-2 (IL-2), regulates cellular immunity and plays a clear antitumor role [33]. This evidence concerns the gene IFNG and neoplasm.