Specifically, in A549 cancer cells, 10 μM genistein combined with 4 Gy X-ray irradiation markedly promoted cellular oxidative damage and apoptosis by restraining CpG island methylation of the Keap1 promoter sequence and reducing nuclear translocation of Nrf2 along with its downstream targets NQO1, HO-1, and GSH, to alleviate radioresistance [89]. This evidence concerns the gene NQO1 and cancer.