CD8A and neoplasm: Thus, by reducing hypoxia-induced M2 TAM hepatocellular carcinoma infiltration, promoting macrophage polarization to M1 TAMs, increasing the number of CD8 + cytotoxic T cells in HCC, and reprogramming the immunosuppressive TME, MnO2 NPs can effectively contribute to the therapeutic strategy for PD-1/PD-L1 immune checkpoints and the effect of whole-cell tumor vaccine immunotherapy [82].