NQO1 and cancer: It functions as an effective cytoprotective agent, a protective antioxidant, and a regulator of the oxidative stressors that cause DNA damage in cancer cells in chromatin-binding proteins.1–3 Upregulation of NQO1 is observed in numerous human cancers.4–8 It is established that the elevation of NQO1 levels has been attributed to the cellular defense response against increased oxidative stress associated with cancer.