Expression of membrane receptors such as CXCR4, a Gi protein-coupled receptor for the ligand CXCL12/stromal cell-derived factor 1α (SDF-1α), has been associated with increased proliferation, invasion and migration in GBM as well as in several other tumors and tumor cell lines [18,19]. This evidence concerns the gene CXCR4 and glioblastoma.