TRAF4 is the fourth member of the TNF receptor associated factor (TRAF) protein family. TRAF proteins are associated with and mediate signal transduction from members of the TNF receptor superfamily. TRAF1 and TRAF2 are two related proteins that form a heterodimeric complex that associates with the cytoplasmic domain of the TNF-receptor type 2. The third member TRAF3 associates with the cytoplasmic domain of CD40. TRAF4 has been shown to interact with neurotrophin receptor, p75 (NTR/NTSR1), and negatively regulate NTR induced cell death and NF-KAPPA B activation. This protein also binds to p47phox, a cytosolic regulatory factor included in a multi-protein complex known as NAD(P)H oxidase. TRAF4 thus, is thought to be involved in the oxidative activation of MAPK8/JNK.