In the optic pathway glioma, SDF-1 is expressed by numerous brain-derived cells including endothelial cells, entrapped axons and infiltrating microglia, which enhances optic glioma cell survival via CXCR4 receptor presented on glioma cells, whereas blocking CXCR4 inhibited glioma development in vivo (92, 93). This evidence concerns the gene CXCR4 and central nervous system cancer.