C3 and systemic lupus erythematosus: Considering that high LRRK2 expression in B cells from SLE patients was strongly correlated with low levels of serum C3 and C4, two indicators related to renal injury during SLE pathogenesis [29], whether decreased total IgG and autoantibodies levels in Lrrk2−/− mice upon pristane treatment led to less kidney pathology was further investigated at 9 months post pristane treatment.