Background：

The innate immune system recognizes microbial pathogens through Toll-like receptors (TLRs)， which identify pathogen-associated molecular patterns. Different TLRs recognize different pathogen-associated molecular patterns and all TLRs have a Toll-interleukin 1 receptor (TIR) domain， which is responsible for signal transduction. The protein encoded by this gene is a TIR adaptor protein involved in the TLR4 signaling pathway of the immune system. It activates NF-kappa-B， MAPK1， MAPK3 and JNK， which then results in cytokine secretion and the inflammatory response. Alternative splicing of this gene results in several transcript variants; however， not all variants have been fully described.