TRAF2 and cancer: TNFR2 is abundantly expressed by certain cancer cells and immune cells, mainly a subset of potent regulatory T cells (Tregs).9 10 TNF activates TNFR2 by recruiting a complex composed of the adapter protein TNF receptor-associated factor 2 (TRAF2) and TRAF2-associated proteins, such as TRAF1, and cellular inhibitor of apoptosis protein (cIAP1/2), which leads to a significant depletion of these complexes in the cytoplasm and thus might affect other activities of these molecules in tumor cells.11