Strikingly, three of the Type 2 cases (Mice 2, 3, and 6) maintained tumor precursor populations with near-2N genomes and normal Pten/chr19 in the SVZ, which carried one or more cNRT2N(s) identical to those observed in autologous sub-4N/Pten/chr19-loss tumors (Fig. 3a). This evidence concerns the gene PTEN and neoplasm.