NFKB1 and systemic lupus erythematosus: Our data showing the effect of UBE2L3 genotype on NF-κB activation in B cells and plasmablast and plasma cell numbers in SLE suggest that UBE2L3 has an important functional role in B cell proliferation and terminal B cell differentiation, consistent with the critical importance of NF-κB activation for B cell lymphoid development41–43 and plasma cell survival.44