IDH1 and glioblastoma: In the updated classification criteria [2], IDH wild-type grade 2–3 diffuse astrocytic glioma without necrosis or microvascular proliferation is also diagnosed as glioblastoma (GBM), IDH wild-type, or WHO grade 4, if any one or combinations of the three conditions of TERT promoter mutation, EGFR amplification, and chromosome 7 amplification/chromosome 10 deletion are met.