CD8A and neoplasm: It improves the generation and survival of tumor-specific T cells [15], enhances the cytotoxicity of natural killer (NK) cells to tumors [16], increases survival and promotes the antibody response of B cells [17], induces the maturation of dendritic cells (DCs) and enhances their ability to cross-present tumor-associated antigens to CD8+ T cells [18,19], negatively regulates the proliferation of regulatory T cells (Tregs) [20], and induces the antigen-presenting cell (APC)-mediated expression of IL-15, which is critical for the proliferation and maintenance of lymphocytes [21].