HIF1A and neoplasm: During adaption to the hypoxic TME, tumor-infiltrating cytotoxic T cells are characterized by high glycolytic rates.503,504 A recent study has found that hypoxia-inducible transcription factor 1α (HIF1α) is essential for the effector state in CD8+ T cells.505 VEGF-deficient CD8+ T cells showed lower efficiency on infiltrating tumors.