However, tumor cells can evade immune surveillance by creating various immunosuppressive microenvironments, such as by downregulating the expression of MHC-I molecules, inhibiting the production of chemokines, or increasing the expression of inhibitory molecules such as PD-L1, all of which limit the infiltration, activation, and cytotoxicity of CD8+ T cells (8–10). This evidence concerns the gene CD8A and neoplasm.