TP53 and neoplasm: In this study, we demonstrate that congenital loss of Trp53 in the mouse brain is sufficient to precipitate spontaneous glioblastoma formation, and that this correlates with upregulation of Pdgfra. Further, we show that ATMIN plays a critical role in GBM formation, promoting Pdgfra protein and gene expression in a Trp53-deficient background, using an in vivo glioma model as well as neural stem cell and primary tumor cell cultures.