HIF1A and neoplasm: Hypoxia rewires T cell metabolism mainly via HIF-1α (96), but the precise in vivo role of HIF-1α in regulation of T cell function remains obscure (97): HIF-1α deficiency in CD8+ T cells enhances fatty acid catabolism and their anti-tumor functions (98), while HIF-1α promotes infiltration of CD8+ T cells into the tumors and enhances their effector responses to persistent antigen and promote tumor clearance (99, 100).