ROS and RNS modulate the activity of the signal transduction pathways and diverse transcription factors involved in cancer initiation and progression, including mitogen-activated protein kinases (MAPKs), phosphoinositide 3-kinase (PI3K)/AKT, protein kinase C (PKC), NF-κB, Nrf2, STAT, HIF-1α, APE1/Ref-1, FOXO, AP-1, p53, and β-catenin [20]. Here, HIF1A is linked to cancer.