CD40 and cancer: Additionally, in light of the observation in other cancer cell types that it is NOX function, but not NOX-mediated ROS production per se, that facilitates TRAF3 induction [11], it is tempting to speculate that rapidly after CD40 cross-linking by mCD40L, direct association (recruitment) of NOX and its catalytic components (including p40phox) with CD40 leads to formation of a pro-apoptotic multi-protein complex.