C3 and systemic lupus erythematosus: The proteinuria level of humanized SLE mice (8–10 weeks old SCID mice engrafted with 3×107 PBLs/mouse from patients with SLE) was significantly reduced after hCDR1 treatment; however, IgG and C3 deposits in the kidney sections were detected in only one (6%) in 17 mice treated with hCDR1 (29).