Contrary to the results of 2-DE immunoblotting, SDS-PAGE, followed by western blotting indicated that the pooled serum from SN-APS patients (numbers 15, 16, and 17) did not react with the commercially available purified C9 and electrophoresed as a single band on SDS-polyacrylamide gel. The gene discussed is C9; the disease is autoimmune polyendocrinopathy.