Isocitrate dehydrogenase (IDH)-wildtype adult-type diffuse astrocytic tumors with EGFR amplification, TERT promoter (TERTp) mutations, or combined gain of chromosome 7 and loss of chromosome 10 can be classified as glioblastomas (GBM), even with low histological grades. The gene discussed is TERT; the disease is glioblastoma.