NFKB2 and rheumatoid arthritis: Although these results suggested that these variants might not exert their effect on RA risk through the modulation of NFKB2- or steroid hormone-mediated immune responses, we could not rule out the possibility of a true effect of these variants on the immune response as their effect might depend on the presence of ACPA (as suggested by our genetic data) or even specific haplotypes.