BCR and systemic lupus erythematosus: There was a trend for B cells from patients with SLE to produce more IL-10 upon TLR9 and BCR cross-linking after pretreatment with F(ab′)2 epratuzumab (608 ± 420 pg/ml vs. 703 ± 452 pg/ml upon F(ab′)2 epratuzumab), which prompted further studies.