TP53 and glioblastoma: We generated murine GBM using the replication-competent avian sarcoma-leukosis virus long terminal repeat with splice acceptor/tumor virus A (RCAS/tv-a) system to express PDGFB and shRNA targeting Tp53 in Nestin-expressing cells of the neonatal Nestin/tv-a (Ntv-a) mouse brain.