Toll-interleukin1 receptor （TIR） domain containing adaptor protein （TIRAP） contains 1 TIR domain. TIRAP is an adapter molecule linked with toll-like receptors. TIRAP is required in TLR2 and TLR4 signaling pathways in the innate immune response. TIRAP activates NF-kappa-B， MAPK1， MAPK3 and JNK， which subsequently results in cytokine secretion and the inflammatory response. TIRAP is highly expressed in the liver， kidney， spleen， skeletal muscle and heart. TIRAP is also found in peripheral blood leukocytes， lung， placenta， small intestine， thymus， colon and brain.
