NFE2L2 and cancer: The double-edged sword role of Nrf2 in response to arsenic toxicity substantiated by excessive ROS formation and increased oxidative stress is (i) protection against oxidative stress by increased expression of antioxidant enzymes and, conversely, (ii) sustained activation of Nrf2 associated with apoptotic resistance, metabolic reprogramming and increased survival of oncogenic cells and cancer development (Niture and Jaiswal 2012).