DNA methylation analysis of 68 glioblastoma specimen of patients treated within clinical trials, 5 samples of normal brain tissue (non-tumor brain) and 4 tumor-derived glioma sphere lines. The data was used to identify changes in DNA methylation which contribute to the aberrant of expression of HOX transcription factors. Our group had previously demonstrated that expression of HOX genes was associated with increased resistance to chemo-radiotherapy and worse outcome in GBM patients Keywords: Disease state comparison Overall design: Bisulphite converted genomic DNA from the 77 samples were hybridised to the Illumina Infinium 450 Human Methylation Beadchip