PADI4 and acute respiratory distress syndrome: The lower NETs level when PAD4 KO was accompanied by reduced ferroptosis in sepsis-associated ARDS mice, as demonstrated by reduced serum levels of ROS (Supplementary Fig. 7B), ferritin (Supplementary Fig. 7C) and labile iron (Supplementary Fig. 7D), reduced MDA and increased GSH levels in lung tissues (Supplementary Fig. 7E and 7F), and increased GPX4 expression detected by qPCR and IHC staining (Supplementary Fig. 7G and 7H).