TNF receptor-associated factor 3 (TRAF3) has many alternative names including CAP-1,CD40 receptor-associated factor 1(CRAF1),CD40-binding protein(CD40BP) and LMP1-associated protein 1 (LAP1). TRAF3 regulates pathways leading to the activation of NF-kappa-B and MAP kinases,and plays a central role in the regulation of innate immune response. It modulates signaling pathways leading to the production of cytokines and interferon. As an essential constituent of several E3 ubiquitin-protein ligase complexes,TRAF3 promote 'Lys-63'-linked ubiquitination of target proteins. Moreover,TRAF3 undergoes both 'Lys-48'-linked and 'Lys-63'-linked ubiquitination in response to various stimuli and is deubiquitinated by OTUB1,OTUB2 and OTUD5.