Ionizing radiation also damages leukocytes situated in the tumor and stimulates the secretion of anti-inflammatory cytokines (TGF-β, IL-6, IL-10, CSF-1), which reduce the antigen-presenting abilities of dendritic cells, reduces T CD8+ lymphocytes cytotoxicity and CD4+ cell differentiation, attracts cancer-associated fibroblasts (CAFs), creates a radioresistant state in tumors and contributes to tumor cells’ proliferation and invasion (22, 48). The gene discussed is CD8A; the disease is neoplasm.