HIF1A and cancer: Accordingly to Negrette-Guzmán, cancer cells generally produce higher ROS levels than normal cells, a feature that stimulates the tumor in its progression and chemoresistance, involving the upregulation of hypoxia-inducible factor-1 alpha (HIF-1α) and nuclear factor-kappa B (NF-κB) (Negrette-Guzmán, 2019).