In this study, we have validated that the GBM-derived epigenetic signature could predict OS in an RT/TMZ cohort of GBM-like LGGs without IDH mutations and 1p/19q codeletions from TCGA (unknown doses of RT and TMZ, p = 0.0077; Additional file 13: Figure S7), its predictive performance however should be further investigated in this LGGs subtype without TMZ therapy. This evidence concerns the gene IDH1 and glioblastoma.