TRAF6 A gene on chromosome 11p12 that encodes an E3 ubiquitin ligase which, together with UBE2N and UBE2V1, synthesises Lys-63-linked-polyubiquitin chains conjugated to proteins, such as IKBKG, AKT1 and AKT2. It also ubiquitinates a free/unanchored polyubiquitin chain, leading to MAP3K7 activation, and activates NF-kappaB and JUN. It may be essential for forming functional osteoclasts and is thought to play a role in dendritic cell maturation and/or activation. It represses c-Myb-mediated transactivation of B cells. It acts as an adapter protein for signal transduction by TNF receptor, as well as IL-1 and IL-17 receptors. It is expressed in the heart, brain, placenta, lungs, liver, skeletal muscle, kidneys and pancreas.