In this regard, a recent study using pancreatic cancer cells has suggested that ROS-induced cytotoxicity upon treatment with pharmacological ascorbate may be partially mediated by dual oxidases 1 and 2 (DUOX1, DUOX2) of the NADPH oxidase (NOX) family of enzymes that not only produce H2O2 but can also be activated by H2O2 [56,92]. The gene discussed is FMO5; the disease is familial pancreatic carcinoma.