Oncogene aberrations drive medulloblastoma progression, not initiation. - Okonechnikov K; Joshi P; Körber V; Rademacher A; Bortolomeazzi M; Mallm JP; Vaillant J; da Silva PBG; Statz B; Sepp M; Sarropoulos I; Yamada T; et al. (Nature, 2025)