FOXR2 and ependymoma: Our analysis showed that the 84 CNS-PNET samples matched with established methylation classes recognized by the Brain Tumor Classifier [5, 6, 23]: (1) CNS neuroblastoma with forkhead box R2 (FOXR2) activation (CNS_NBL; n = 20; 24%): (2) Glioblastoma, IDH wild-type, subclass H3.3 G34 mutant (GBM_G34; n = 22; 26%); (3) Glioblastoma, IDH wild-type, subclass MYCN (GBM_MYCN; n = 18; 21%), and (4) Ependymoma, with RELA_C11orf95 fusion (EPN_RELA; n = 24; 29%).