VEGFA and glioblastoma: This paracrine relationship involving GBM stem cells and the neo-vasculature is particularly interesting since recent studies suggest beneficial effects of anti-angiogenic treatments with either the humanized VEGF-neutralizing antibody bevacizumab (Avastin) or the pan-VEGF receptor tyrosine kinase inhibitor cediranib (AZD2171) in recurrent high-grade glioma [108-110].