TRAF1 and anaplastic large cell lymphoma: Consistent with studies of the TRAF1-ALK fusion protein in ALCL, transgenic mice overexpressing TRAF1 in T cells exhibit decreased antigen-induced apoptosis of CD8 T cells (35), while TRAF1−/− mice display impaired survival and altered proliferation of T cells in response to the 4-1BB-NF-κB2 and T cell receptor (TCR)-NF-κB1 signaling pathways, respectively (29, 31–34).