MMP9 and systemic lupus erythematosus: According to receiver operating characteristic (ROC) analysis, the diagnostic efficiency of the MMP9 promoter methylation level for SLE was 0.839 while the RUNX3 promoter methylation level for SLE was 0.769, emphasizing the potential utility of MMP9 and RUNX3 methylation levels as biomarkers for SLE diagnosis (25, 26).