Under serum-starved conditions, lung cancer cell lines that lack DUOX1 (A549, H187) show detectable basal EGFR activity (as assessed by Y1068 autophosphorylation, a read-out of EGFR kinase activation), whereas this is largely absent in normal bronchial epithelial cells28 or H292 cells (with epithelial characteristics) that express DUOX1 (Fig. 1a). Here, DUOX1 is linked to lung cancer.