According to the above results that IgG but not IgA or IgM anti-HRGEC antibody serum levels in LN patients were significantly higher than that in SLE patients without LN, we initiated the efforts to generate monoclonal IgG anti-HRGEC antibodies from LN patients with high titers of such antibodies and finally obtained 4 monoclonal antibodies (LN1–4). The gene discussed is CD79A; the disease is systemic lupus erythematosus.