A study involving 123 patients with SLE who were evaluated clinically, with magnetic resonance imaging (MRI) and CSF analyses of MMP-9 found significant correlation between MMP-9 and intrathecal levels of tau and glial fibrillary acid protein, markers of neuronal degradation, suggesting ongoing neurodegeneration in the brains of NPSLE patients with high expression of MMP-9 (68). Here, MMP9 is linked to systemic lupus erythematosus.