The clinical relevance of DUOX1 suppression in lung cancer is also supported by a recent study of patients with hepatocellular carcinoma, which indicated that higher DUOX1 expression strongly correlated with disease-free survival.44 However, as our various observations were based on experimental cell models, the clinical relevance of our findings with respect to, for example, tumor stage or progression is still unclear. This evidence concerns the gene DUOX1 and lung carcinoma.