Wild-type (wt) and dominant-negative (dn) forms of MyD88 and Mal/TIRAP used in the present study. MyD88wt contains an N-terminal DD and a C-terminal TIR domain, whereas Malwt lacks a DD but still contains a C-terminal TIR domain. MyD88dn has a point mutation (Phe56Asn) and a 52–amino acid deletion spanning its DD that disrupts DD-DD interactions. Maldn has a point mutation (Pro125His) in its TIR domain that disrupts TIR domain interactions. MalTIR consists only of the Mal/TIRAP TIR domain.