Background：Functions as sorting adapter in LPS-TLR4 signaling to regulate the MYD88-independent pathway during the innate immune response to LPS. Physically bridges TLR4 and TICAM1 and functionally transmits LPS-TRL4 signal to TICAM1; signaling is proposed to occur in early endosomes after endocytosis of TLR4. May also be involved in IL1-triggered NF-kappa-B activation, functioning upstream of IRAK1, IRAK2, TRAF6, and IKBKB; however, reports are controversial. Involved in IL-18 signaling and is proposed to function as a sorting adaptor for MYD88 in IL-18 signaling during adaptive immune response.
Isoform 2: Proposed to inhibit LPS-TLR4 signaling at the late endosome by interaction with isoform 1 thereby disrupting the association of isoform 1 with TICAM1. May be involved in TLR4 degradation in late endosomes.
