Therefore, a role of MMP-9 in SLE pathology might be suspected.8 Serum level of MMP-9 in 36 SLE patients was tested and it was discovered that serum level of MMP-9 was significantly decreased in patients as compared to those in controls, and was lower in patients with active disease than those with inactive disease. This evidence concerns the gene MMP9 and systemic lupus erythematosus.