Independent genome-wide DNA methylation profiling of short- (<1 y) and long-term survivors (>3 y) with the HumanMethylation450 K array has confirmed a G-CIMP positive phenotype that was tightly associated with the IDH1 mutation and has identified a set of differentially hypermethylated CpG loci between long and short term GBM survivors, including members of the HOX genes, and NR2F2 and TFAP2A genes coding for the transcription factors8. Here, IDH1 is linked to glioblastoma.