In the present study, using both an in vivo ALI mouse model and the in vitro culture of AMΦ from TLR4−/− and MyD88−/− mice, we demonstrate that LPS up-regulation of TLR3 in AMΦ is dependent on TLR4-MyD88-NF-κB signaling. The gene discussed is TLR3; the disease is acute respiratory distress syndrome.