Similar to that in tonsil B cells, CD154 stimulation could induce further NF-κB activation in B cells from lupus patients, including phosphorylation and degradation of IκB-α and phosphorylation of P65 (Fig. 3B), as well as nuclear translocation of P65 but not P50 or c-Rel (Fig. 3C). Here, CD40 is linked to systemic lupus erythematosus.