There is evidence that a direct association exists between increased expression of MMPs and tumor invasiveness, angiogenesis, development of metastases, and decreased survival time.[83] The levels of MMP‐2 and MMP‐9 are specially related to tumor progression in human gliomas,[84] with MMP‐2 being primarily involved in both invasion and angiogenesis and MMP‐9 contributing mostly to tumor neovascularization, due to their cellular origin and localization.[85] Several factors are known to upregulate MMP expression. This evidence concerns the gene MMP2 and central nervous system cancer.