CD8A and neoplasm: Radiation could induce cell death at the local area by causing DNA damage, and this process was termed “immunogenic cell death”, and then, the damage-associated molecular patterns (DAMPs), chemokines and some tumor-associated antigens were released in TEXs [4], which were processed by antigen-presenting cells including macrophages and dendritic cells to trigger the activation of CD8+ T cells; thus, the CD8+ T cells could kill the distant metastasis tumor cells through circulation [1].