HIF1A and neoplasm: of the effect of oncogenes in the EGFR family that modulate hypoxia-mediated radio-resistance on the alpha-subunit of HIFs and also the reverse, acquired resistance to EGFR tyrosine kinase associated with increased HIF-1α levels HIF-1 modulates tumor resistance by manipulating several signaling pathways downstream, with reprogramming of tumor metabolism, vasculogenesis, and epithelial-mesenchymal transition being the most important events associated with tumor response to irradiation.