HIF1A and lung adenocarcinoma: To examine the effect of CSE on HIF-1, human lung adenocarcinoma A549 (Fig. 1a and Supplementary 1 and 2a) and human bronchial epithelial BEAS-2B cells (Fig. 1b and Supplementary 2b) were exposed to 2% CSE under non-hypoxic (20% O2), 100 μM desferrioxamine (DFX) or hypoxic (1% O2) conditions for 4 h.