TNFSF13B and rheumatoid arthritis: Although belimumab was therapeutic in a clinical phase I/II study in RA patients and was approved by the FDA to treat SLE patients, patient heterogeneity has limited its clinical phase III study.13 Meanwhile, Atacicept (TACI-Fc) can cause infections, related to the rapid decline of serum IgG.13,42 In this study, we did not observe obvious immunopathology in mice treated with BAFF-Trap.