Our data suggest that the remarkable response observed in phase I studies with the ITs, TP-38 (patient surviving > 5 years post-therapy) [37] and IL13-PE38QQR (prolonged progression-free survival beyond one and two years in 15/46 glioblastoma patients) [38] could be attributed to IT-mediated induction of T cell immune response. This evidence concerns the gene IL13 and glioblastoma.