BO treated rats, particularly those given a high dosage (HBO), had reduced mRNA expression of lipid anabolism-related genes, toll-like receptor 4 (TLR4), lipid inflammatory-related genes, nuclear factor kappa beta (NF-B), and monocyte chemoattractant protein (MCP)-1 while increasing mRNA expression of lipid catabolism-related genes and peroxisome proliferator-activated receptor-gamma mRNA (PPAR mRNA). This evidence concerns the gene TLR4 and bronchiolitis obliterans syndrome.