ETMR are molecularly characterized by distinct DNA methylation signatures and dysregulated expression of oncogenic miRNAs.2,3 Amplifications of 19q13.42 encoding the primate-specific miRNA cluster C19MC are the most frequent recurrent genomic alterations in ETMR.5,7,8 Remaining cases often harbor mutations affecting DICER1, a ribonuclease involved in miRNA processing.2,9,10 Recently, dysregulated miRNA processing has been linked to R-loop-associated chromosomal instability and upregulated DNA repair mechanisms in ETMR.2,6. The gene discussed is DICER1; the disease is ependymoblastoma.