In addition, radiation-induced inflammation reduces tumor-suppressing immune cells such as CD4+T cells, CD8+T cells, and natural killer (NK) cells, while tumor-promoting immune cells such as regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and M2 tumor-associated macrophages (TAMs) increase, eventually forming an immunosuppressive environment, and high level of TGFβ (19, 63). This evidence concerns the gene CD8A and neoplasm.