HIF1A and neoplasm: Rapidly proliferating tumor cells experience chronic hypoxia and reduced O2 availability that, in turn, induce HIF-1α, which regulates the transcription of a plethora of gene encoding proteins involved in every aspect of cancer biology including carcinogenesis, cell transformation; cell proliferation, genome instability/DNA mutation, inflammation, glucose and energy metabolism, angiogenesis, autocrine growth factor signaling, invasion, metastasis, immune evasion, stemness, and resistance to chemo- and radiation therapy [105,122,125,126,127,128,129,130,131,132,133].