It is worth noting that EGFR amplification, gain of chromosome 7, monosomy 10, PTEN mono- or bi- allelic deletions, and mutations of TERT promoter (TERTp), typically occur in grade IV, i.e. glioblastoma (GBM), and in IDH1/2-wildtype (IDHwt) grade II/III, i.e. diffuse/anaplastic astrocytomas (DA/AA), where their prognostic impact is still debated4–6. Here, IDH1 is linked to glioblastoma.