GPX4 and cystic fibrosis: In summary, our novel findings indicate that IB3-1 cystic fibrosis AECs are much more susceptible to cell death by ferroptosis than their cognate C38 AECs, which appears underpinned by abnormal intracellular accumulation of ferrous iron, and decreased antioxidant defences, as manifested by low GSH and GPX4 levels, and unrestrained lipid peroxidation.