CD8A and cancer: There are several mechanisms in which immunosuppression may be introduced in the tumors, such as CD8+ T cells inhibition by regulatory T cells (Tregs), secretion of IL-10/IL-6 with inhibition of PD-1 receptor, immunosuppressive actions of myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), or cancer-associated fibroblasts (CAFS).