In order to investigate whether NF-κB signaling is constitutively activated, the expression of endogenous NF-κB signaling subunits (IκBα, pIκBα, IκBβ, IκBδ, P65 and pP65) were measured and compared between B cells from normal controls and SLE patients. Here, NFKBIB is linked to systemic lupus erythematosus.