We found that the de novo RRD glioblastomas had unique hypomethylated genomes in comparison to the conventional IDH-wildtype glioblastomas, with several thousand recurrently hypomethylated CpG sites shared across the 7 de novo RRD glioblastomas versus the conventional glioblastomas (Fig. 4, Supplementary Table S5). The gene discussed is IDH2; the disease is glioblastoma.