HIF1A and neoplasm: Tumor cells adapt to the high reactive oxygen environment and avoid cell death by inducing the secretion of inflammatory cytokines, stabilizing hypoxia-inducible factor-1α (HIF-1α), activating AMP-activated protein kinase (AMPK) signaling, and promoting the production of nicotinamide adenine dinucleotide phosphate (NADPH), which in turn promotes tumor metastasis and angiogenesis (40).