TAK1 and the IKK complex are observed to migrate from the cytosol to lipid rafts containing the CARMA1:BCL10:MALT1 (CBM) complex (Sommer et al. 2005, Shinohara et al. 2005 using chicken cells). By analogy with activation of NF-KappaB signaling in T cells, TAK1 in B cells may also be bound to TAB1 and TAB2 or TAB3, which bind K63-conjugated polyubiquitin on a TRAF protein bound to the CBM complex (reviewed in Shinohara et al. 2009).