TNFSF13B and systemic lupus erythematosus: Iberdomide (CC-220) is a high-affinity cereblon ligand that promotes ubiquitination and subsequent degradation of Aiolos and Ikaros by the proteasome.11 In B cells from healthy donors and patients with SLE, iberdomide reduces Aiolos and Ikaros protein levels, thereby inhibiting BAFF-induced and CD40L-induced proliferation, plasmablast differentiation and IgG secretion in vitro.7 In cultures of peripheral blood mononuclear cells from patients with SLE, iberdomide inhibited anti-dsDNA and anti-phospholipid IgM autoantibody production in vitro.6