Since some of those mutations have been used to molecularly classify glioblastoma (EGFR amplification associated with classical, NF1 and TP53 mutations with mesenchymal or IDH1 mutation with proneural subtypes), these results also suggest that plasma ctDNA analysis might be an option to obtain actionable somatic genomic information and reveal the molecular profile or subtypes of glioblastoma patients. Here, IDH1 is linked to glioblastoma.