Studies suggest TLR3 has little role in CLP-induced ALI, as its transcript level decreases in septic murine lungs, and TLR3 deletion does not protect CLP-treated mice from ALI.485,495 On the other hand, TLR7 in macrophages senses extracellular miRNA-146a-5p, triggers pulmonary inflammation and endothelial barrier dysfunction via TNF, contributing to sepsis-induced ARDS.496 Besides, MDA5 promotes nuclear translocation of IRF3 to initiate the transcription of signal transducer and activators of transcription 1, activating macrophage M1 polarization in septic ALI.497. Here, TLR7 is linked to acute respiratory distress syndrome.