PPM1D and medulloblastoma: Previously described focal alterations characteristic for SHH tumors including amplification of MYCN/GLI2/CDK6/YAP1/PPM1D, and deletions targeting PTCH1/CDKN2A/CDKN2B/PTEN were largely confined to TERT wild-type SHH medulloblastomas, while TERT mutant SHH (Fig. 5) and Group 4 (Supplementary Figure 3) showed very few focal SCNAs.