Clustering of 396 high‐grade gliomas confirmed these three subtypes [6], here defined Cluster M1 (with 60% enrichment for MES), M3 (58% enrichment for CL), and M5 (mainly enriched for PN glioblastoma, but also including IDH‐mutant tumours, now referred to as astrocytoma IDHmut CNS WHO grade 4 in the 2021 WHO classification) (Fig. 2). The gene discussed is IDH1; the disease is glioblastoma.