Tumor cells begin to secrete matrix metalloproteinases (MMP), particularly MMP‐2 and MMP‐9, which act as zinc‐dependent endopeptidases that specifically degrade extracellular matrix components such as collagen IV (MMP‐2 action) and laminin (MMP‐9 action) of the vascular basement membrane, resulting in structural disruption and weakening of the vascular wall.[78] At the same time, GBM cells undergo adaptive morphological and cytoskeletal changes within the cell, extending pseudopods and enhancing interactions with endothelial cells. This evidence concerns the gene MMP9 and glioblastoma.