FMO5 and lung cancer: The main finding of the present studies is that they establish the potential significance of frequent observations of epigenetic silencing of the NADPH oxidase DUOX1 in lung cancer and in other epithelial-derived cancers,18, 20, 21, 44 and indicate that DUOX1 silencing is causally linked with the development or progression of EMT, and promotes invasive properties, as well as CSC features and resistance to EGFR TKIs.