MKI67 and neoplasm: It was found that the proportion of Ki67+CD8+ T cells increased in both primary and distal tumor after IR treatment, especially in the tumor of PD-L1−/− mice (Figures 4A and 4B), indicating that the proliferation ability of intratumoral CD8+ T cells could be promoted by IR, which was further enhanced under the situation of PD-L1 deficiency.