Furthermore, we hypothesized that the BBB disruption, combined with the presence of numerous immature blood vessels and elevated VEGF and MMP-2 expression in GBM tissues, resulted in a higher MVD, larger vascular bed area, faster blood flow velocity, and increased tumor vascular permeability, which may have caused leakage of the contrast agent molecules from the blood vessels. This evidence concerns the gene MMP2 and glioblastoma.