IDH1 and glioblastoma: Analyzing 450 K data of 93 samples from The Cancer Genome Atlas (TCGA, data set “glioblastoma multiforme” excluding IDH1 mutants), we could not confirm any prognostic value of CpG − 48 which is represented as cg01341123 (p = 0.9056) (Additional file 6: Fig. S3b, for location compare Additional file 4: Fig. S2a).