IKZF1 and rheumatoid arthritis: On the other hand, CRL4CRBN promotes the degradation of IKZF1, IKZF3, or c-Jun, which leads to the reduction of the secretion of IgG or the pro-inflammatory cytokines COX-2, iNOS, IL-1β, and IL-6, consequently attenuating SLE or RA (70, 138) (Table 1).