TLR4 and acute respiratory distress syndrome: Bacterial and viral inflammation, signalling through TLR4 and TLR7/8, causes exacerbations of a range of different respiratory diseases, including COPD, asthma and ILDs, and plays a key role in the initiation of ARDS (Jain et al., 2023; Jha et al., 2021; Lin et al., 2022).