KDR and central nervous system cancer: CXCL2 is another ligand of CXCR2 and, in recent reports, the axes CXCL2-CXCL8/CXCR2 is described as an important signaling pathway modulating GBM angiogenesis, alternative to the well-known VEGF-VEGFR one, thus representing a new target for glioma therapy.