Th1 s can directly kill tumor cells by releasing cytokines that activate death receptors on the surface of tumor cells, enhance the CD8 T cell response, and contribute to the recruitment of natural killer cells and type I macrophages to the tumor (Knutson and Disis, 2005; LaCasse et al., 2011; Kim and Cantor, 2014). This evidence concerns the gene CD8A and neoplasm.