When comparing subtypes based solely on RNA expression, oligoneural precursors correspond to the proneural GBM subtype due to mutations in isocitrate dehydrogenase 1 (IDH1), mesenchymal neural precursors correspond to the mesenchymal GBM subtype due to mutations in NF1, and radial glial may correspond to the classic GBM subtype due to high levels of EGFR. This evidence concerns the gene IDH1 and glioblastoma.