CD4 and neoplasm: The chlorine e6 and doxorubicin-loaded hollow manganese dioxide nano platform (H-MnO2-PEG/C&D) can relieve tumor suppression whereas checkpoint-blockade (PD-L1 blockade) promotes the higher TNF-α secretion and augmented CD4+ and CD8+ T cells-mediated immune response than chemo-PDT therapy 81.