PCNA and systemic lupus erythematosus: The routine autoimmune assays performed for systemic autoimmune diseases (including antinuclear antibody (ANA), anti-PCNA antibody, anti-dsDNA antibody, ENA (Extractable Nuclear Antigen) panel, anti-mitochondrial antibody (AMA); anti-smooth muscle antibody, Anti-cytoplasmic antibody (ANCA) panel, anti-MPO and anti-PR3 antibodies, LKM (Liver-Kidney Microsomal) antibody, anti-centromere antibody) yielded negative results, and there was no evidence of lupus anticoagulant or anti-cardiolipin antibodies.