The ratio between MMP-9 and MMP-2 was proposed as a serum marker to monitor the progression of liver disease, and the ratio between MMP-2 and MMP-9 was associated with poor response to chemotherapy in osteosarcoma in two previous studies [39, 40]; however this is the first time that the ratio between the active forms of MMP-9 and MMP-2 was calculated in MS patients, and for this reason further studies are required to investigate the biological significance of the imbalance between serum levels of gelatinases. This evidence concerns the gene MMP9 and liver disorder.