Clark et al. carried out genomic analyses of 775 meningiomas and found recurrent mutations in POLR2A, which encodes the catalytic subunit of RNA polymerase II, an essential enzyme that mediates the transcription of all protein-coding genes in eukaryotic cells. Mutant POLR2A allows tumours to hijack the transcriptional machinery and drive neoplasia. The authors found additional mutated genes that define distinctive meningioma subgroups with different clinical features.