CD8A and neoplasm: The PDT + αPD–L1 group significantly ameliorated the immune environment of the 4T1 tumor of mice by promoting the activation of mDCs from 0.023% to 0.077% and enhancing the infiltration of CTLs from 0.23% to 0.92% and the CD8+GranB+ T cells from 0.39% to 1.29% compared with the PBS group.