CD8A and malignant colon neoplasm: Triple therapy not only recruits CD8+ T lymphocytes and NK cells into tumors to induce the production of IFN-γ and IL-12, but also increases the expression levels of Fas cell surface death receptor (FAS) and caspase-3, thereby inducing apoptosis of colon cancer cells, inhibiting colon cancer cell metastasis, effectively exerting anti-tumor activity and improving survival (Kim et al., 2012) (Figure 2).