The function of Ensembl gene identifier ENSG00000175104 (TRAF6, TNF receptor associated factor 6) is as follows. E3 ubiquitin ligase that, together with UBE2N and UBE2V1, mediates the synthesis of 'Lys-63'-linked-polyubiquitin chains conjugated to proteins, such as ECSIT, IKBKG, IRAK1, AKT1 and AKT2 (PubMed:11057907, PubMed:18347055, PubMed:19465916, PubMed:19713527, PubMed:27746020, PubMed:31620128). Also mediates ubiquitination of free/unanchored polyubiquitin chain that leads to MAP3K7 activation (PubMed:19675569). Leads to the activation of NF-kappa-B and JUN (PubMed:16378096, PubMed:17135271, PubMed:17703191, PubMed:39920527). Seems to also play a role in dendritic cells (DCs) maturation and/or activation (By similarity). Represses c-Myb-mediated transactivation, in B-lymphocytes (PubMed:18093978, PubMed:18758450). Adapter protein that seems to play a role in signal transduction initiated via TNF receptor, IL-1 receptor and IL-17 receptor (PubMed:12140561, PubMed:19825828, PubMed:8837778). Regulates osteoclast differentiation by mediating the activation of adapter protein complex 1 (AP-1) and NF- kappa-B, in response to RANK-L stimulation (By similarity). Together with MAP3K8, mediates CD40 signals that activate ERK in B-cells and macrophages, and thus may play a role in the regulation of immunoglobulin production (By similarity). Acts as a regulator of the JNK and NF-kappa-B signaling pathways by initiating assembly of heterotypic 'Lys-63'-/'Lys-48'-linked branched ubiquitin chains that are then recognized by TAB2: TRAF6 catalyzes initial 'Lys-63'-linked- polyubiquitin chains that are then branched via 'Lys-48'-linked polyubiquitin by HUWE1 (PubMed:27746020). 'Lys-63'-/'Lys-48'-linked branched ubiquitin chains protect 'Lys-63'-linkages from CYLD deubiquitination (PubMed:27746020). Participates also in the TCR signaling by ubiquitinating LAT (PubMed:23514740, PubMed:25907557). {ECO:0000250|UniProtKB:P70196, ECO:0000269|PubMed:11057907, ECO:0000269|PubMed:12140561, ECO:0000269|PubMed:16378096, ECO:0000269|PubMed:17135271, ECO:0000269|PubMed:17703191, ECO:0000269|PubMed:18093978, ECO:0000269|PubMed:18347055, ECO:0000269|PubMed:18758450, ECO:0000269|PubMed:19465916, ECO:0000269|PubMed:19675569, ECO:0000269|PubMed:19713527, ECO:0000269|PubMed:19825828, ECO:0000269|PubMed:23514740, ECO:0000269|PubMed:25907557, ECO:0000269|PubMed:27746020, ECO:0000269|PubMed:31620128, ECO:0000269|PubMed:39920527, ECO:0000269|PubMed:8837778}.