NFE2L2 and hepatocellular carcinoma: Among the genes downstream of NRF2 involved in the development of radioresistance, HO-1 appears to be induced by an increase of nuclear NRF2 in lung cancer (174) and to be down-regulated, together with NQO-1, as a result of NRF2 inhibition in hepatocellular carcinoma (175, 176) and in esophageal squamous cell carcinoma (177).