A potentially effective therapeutic strategy may derive from the finding that the transmembrane prostate specific membrane antigen (PSMA) is robustly expressed by the tumor vascular endothelium in a variety of solid cancers, including GBM and primary adenocarcinoma of the breast, but is not evident in normal vascular endothelium, and to only very low levels in normal prostate [9-13]. This evidence concerns the gene FOLH1 and glioblastoma.