We further analyzed the correlation of titer of anti-MDM2 and European Sjogren's syndrome disease activity index (ESSDAI) [12], complement 3 (C3), complement 4 (C4), immunoglobulin and other laboratory findings including level of platelet (PLT), hemoglobin (HB) and white blood cell count (WBC). This evidence concerns the gene C4A and Sjogren syndrome.