The presence of at least one of the following: (i) EGFR gene amplification; (ii) chromosome 7 gain plus chromosome 10 loss; (iii) hotspot TERT promoter mutation, considered molecular markers of GBM, is sufficient to define an IDH wild-type diffuse glioma as GBM, independently of its histological appearance [4,18], although this remains partly disputed [17]. The gene discussed is IDH1; the disease is glioblastoma.