The very aggressive ETMR are supra- or infra-tentorial tumors of early childhood and share features with the also aggressive CNS BCOR-ITD; while ETMR are characterized by the amplification of an miRNA cluster on chromosome 19 (C19MC amplification), CNS BCOR-ITD harbor an internal tandem duplication of the BCOR gene. Here, BCOR is linked to ependymoblastoma.