Preoperative sera MMP-9 levels were significantly higher in glioblastoma patients (median: 2.8 ng/ml, IQR: 2.1-3.7, p<0.001) compared to BM (1.8 ng/ml, IQR: 1.3-2.3), meningioma (1.2 ng/ml, IQR: 0.9-1.4), and healthy individuals (0.8 ng/ml, IQR: 0.6-1.0). This evidence concerns the gene MMP9 and meningioma.