The protein encoded by this gene is an activator of MAP3K7/TAK1, which is required for for the IL-1 induced activation of nuclear factor kappaB and MAPK8/JNK. This protein forms a kinase complex with TRAF6, MAP3K7 and TAB1, and it thus serves as an adaptor that links MAP3K7 and TRAF6. This protein, along with TAB1 and MAP3K7, also participates in the signal transduction induced by TNFSF11/RANKl through the activation of the receptor activator of NF-kappaB (TNFRSF11A/RANK), which may regulate the development and function of osteoclasts. Studies of the related mouse protein indicate that it functions to protect against liver damage caused by chemical stressors. Mutations in this gene cause congenital heart defects, multiple types, 2 (CHTD2). Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2014]