Consistent with a higher activity of S-phase genes and MYC target genes and poorer overall survival26 (Extended Data Fig. 6i–k), we estimated shorter tumour doubling times in medulloblastomas at the group 3 pole as compared with tumours at the group 4 pole (Extended Data Fig. 6j), confirming our modelling approach. The gene discussed is MYC; the disease is medulloblastoma.