Parada et al. induced resultant malignant astrocytoma via early inactivation of Tp53 and Nf1 in mice [30], and demonstrated that manipulation of tumor suppressors (Nf1, Tp53, and Pten) in NSCs and NPCs in vivo is both necessary and sufficient for the formation of astrocytomas (Fig. 1). This evidence concerns the gene TP53 and neoplasm.