The administration of 10 mg/kg bevacizumab for 3 weeks resulted in a significant increase in invasive tumor cells outside the tumor rim, visualized by vimentin staining (Figure 3), suggesting that anti-VEGF treatment induced an increased ability of cell migration and invasion both in cultured C6 cells and in intracranial C6 glioma cell xenograft. This evidence concerns the gene VEGFA and central nervous system cancer.