Fig. 3. Role of hypoxia in antitumor immunity. Oxygen tension decreases close to the tumor core. Under normoxia, antitumor immunity occurs normally. Under hypoxia, oxygen deprivation induces tumor cell invasion, radioresistance, and necrosis. Immune cells also undergo hypoxia. The metabolic fitness of immune cells is disrupted. Immunosuppression resulting from M2 macrophage polarization and T cell exhaustion is mediated by hypoxia.
