PDCD1 and neoplasm: Inhibition of Foxp3 T cell differentiation and/or survival and promotion of Teff cell IFNγReduction of granulocyte MDSCs and regulatory T cells in the TME. Increase in tumor-infiltrating CD4+ T cells.Increases OXPHOS activity and aerobic glycolysis in activated CD8+ T. Inhibits OXPHOS and glycolysis in G-MDSC.Mitigates hypoxia and synergizes with ICB antibody against PD-L1Tumor hypoxia normalization to enhance the efficacy of anti-PD-1 therapy.