When edited NPCs were engrafted in the brains of four Nod scid mice, PTEN−/−;NF1−/− NPCs and TP53−/−;PDGFRAΔ8–9 NPCs each formed brain tumors with median survival of 141, and 119.5 days, respectively (Fig. 1f). The gene discussed is TP53; the disease is brain neoplasm.