PTEN and neoplasm: Importantly, the near-2N/Pten/chr19-loss tumor precursor cells in Mice 5 and 10 also carried one copy of the cNRT2N(s) (cNRT2N-1×) identical to the one(s) presented with two copies observed in autologous sub-4N/Pten/chr19-loss tumors (cNRT2N-2×) (Fig. 3a and Supplementary Fig. 4).