TLR4,also named as CD284,belongs to the Toll-like receptor family. TLR4 cooperates with LY96 and CD14 to mediates the innate immune response to bacterial lipopolysaccharide (LPS). TLR4 acts via MYD88,TIRAP and TRAF6,leading to NF-kappa-B activation,cytokine secretion and the inflammatory response. Three alternatively spliced transcript variants that encode different protein isoforms have been described.