CD8A and neoplasm: Accumulating evidence indicates that immune response components, such as immune-related signals and immune cells, including both tumor-promoting regulatory T cells (Treg) or myeloid-derived suppressor cells (MDSCs), tumor-antagonizing effector T cells (including CD8+ cytotoxic T cells and effector CD4+ T cells), natural killer (NK) cells, dendritic cells (DCs), and tumor associated macrophages (TAMs), are an integral part of the microenvironment of most cancer tissues, even those that are not causally linked to inflammation [113].