Anti-SS-A and anti-SS-B are related to Sjögren’s syndrome[10]; anti-dsDNA, anti-nucleosome, anti-Sm, anti-Ribosome P and anti-PCNA autoantibodies are associated with systemic lupus erythematosus (SLE)[11,16,17]; anti-RNP autoantibodies are correlated with mixed connective tissue disease[12]; anti-centromere, anti-Scl-70 and anti-Ku are associated with systemic sclerosis, and anti-Jo-1 autoantibodies are found in myositis [13,18,19]. The gene discussed is PCNA; the disease is systemic lupus erythematosus.