Enables CD40 receptor binding activity. Involved in several processes, including interleukin-17-mediated signaling pathway; positive regulation of signal transduction; and regulation of gene expression. Acts upstream of or within several processes, including cellular response to nitric oxide; programmed necrotic cell death; and regulation of JNK cascade. Located in several cellular components, including cytoplasmic side of plasma membrane; membrane raft; and vesicle membrane. Part of CD40 receptor complex and IRE1-TRAF2-ASK1 complex. Is expressed in several structures, including genitourinary system; lower jaw tooth; and mandibular process. Orthologous to human TRAF2 (TNF receptor associated factor 2). [provided by Alliance of Genome Resources, Apr 2022]