In the current study, we have examined the frequency and the pathogenic relevance of anti-C1q, anti-C1r, anti-C1s and anti-C1-Inh autoantibodies in LN patients confirmed via biopsy, in order to ascertain if autoantibodies against all subcomponents of the C1 complex have any prognostic value in the disease. This evidence concerns the gene C1S and lobular neoplasia.