C3 and lobular neoplasia: In this prospective study, serum samples at renal biopsy and after the induction therapy of 107 LN patients were tested for a panel of autoantibodies (including anti-dsDNA, anti-C1q, anti-nucleosome, anti-ribosome antibodies, and C3 and C4 complement fractions) to investigate their association with the clinical and histological data.