MMP9 and central nervous system cancer: Although the mechanism via which MMP-9 and IL-8 induce inflammatory stimuli glioma angiogenesis remains to be better understood, it would be of great interest to further evaluate whether and how in gliomas they cooperates with VEGF-C to promote neovascularization, due to the fact that these key angiogenic factors are all subject to the modulation of one upstream regulator, Bmi-1.