Adapter linking MAP3K7/TAK1 and TRAF6. Promotes MAP3K7 activation in the IL1 signaling pathway. The binding of 'Lys-63'- linked polyubiquitin chains to TAB2 promotes autophosphorylation of MAP3K7 at 'Thr-187'. Involved in heart development. Interacts with MAP3K7 and TRAF6. Identified in the TRIKA2 complex composed of MAP3K7, TAB1 and TAB2. Binds 'Lys-63'-linked polyubiquitin chains. Interacts with NCOR1 and HDAC3 to form a ternary complex. Interacts (via C-terminal) with NUMBL (via PTB domain). Interacts (via the C-terminus) with WDR34 (via WD domains). Interacts with RBCK1. Widely expressed. In the embryo, expressed in the ventricular trabeculae, endothelial cells of the conotruncal cushions of the outflow tract and in the endothelial cells lining the developing aortic valves. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.