PPM1D and brain stem glioma: In contrast, C-terminal truncation of Ppm1d by sgPpm1dexon6 was sufficient to generate fully penetrant brainstem gliomas, with all mice developing neurological symptoms (17/17) with a median survival of 44 days, representing a significantly shorter latency (P < 0.0001 log rank Mantel–Cox test) (Fig. 1D).