Acts as an adapter to assemble/stabilize a Toll/wek/Myd88/tube complex; required for efficient recruitment of Myd88 to Toll. Dispensable for innate immune response; plays a minimal role, if any, in the immune defense against Gram-positive bacteria and fungi. Involved in dorsoventral axis determination. Homodimer. Interacts with Myd88 and Toll. Localizes to the plasma membrane in embryos when bound to Myd88.