For example, in clinical trials of the vascular endothelial growth factor- (VEGF-) neutralizing antibody bevacizumab in glioblastoma, 40% to 60% of the tumors progressed after initially successful treatment [51], consistent with the development of resistance to antiangiogenic therapy, a state exhibiting a poor prognosis and poor response to available treatments [52]. This evidence concerns the gene VEGFA and glioblastoma.