TRAF6 and neoplasm: TRAF6 and TRAF3 are critical for signal transduction in the NF-κB signaling pathway induced by LPS, IL-1β, and TNF-α.34 Moreover, in our previous study, we found that CD40 activates the immune response for organ transplantations and tumor cells.20 35 In a study by Pullen et al,36 CD40 was shown to bind to TRAF6 and TRAF3 proteins via its cytoplasmic domain, suggesting that CD40 activated the NF-κB signaling pathway in a TRAFs-dependent manner.