TAB2 (TGF-beta-activated kinase 1 and MAP3K7-binding protein 2) 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 comple, Xenopus/Amphibian, with TRAF6,Mouse,AP3K7 and TAB1, thus serves as an adaptor linking MAP3K7 and TRAF6. TAB2 with TAB1, and MAP3K7 also participate in the signal transduction induced by TNFSF11/RANKl through the activation of the receptor activator of NF-kappB (TNFRSF11A/RANK), which may regulate the development and function of osteoclasts.