The purposes of the current study are (1) to observe the neutrophil TLR4 expression in patients to provide clues for TLR4 involved in ALI after OLT; (2) to dynamically investigate the changes in lung pathology, TLR4 expression, and inflammatory mediators in lung tissue during orthotopic autologous liver transplantation (OALT) in a rat model; (3) to evaluate the relative importance of TLR4 in the development of ALI during OLT using RNA interference (RNAi), which is an established method for inhibiting target gene expression in a rat model [14, 15]. Here, TLR4 is linked to acute respiratory distress syndrome.