Some of the major changes were the re-defining of glioblastoma, IDH-wildtype, WHO grade 4 (6, 7), the re-grading of astrocytoma, IDH-mutant (5), and the systemic categorization of pediatric-type diffuse gliomas based on their well-established genetic alterations (9–11). The gene discussed is IDH1; the disease is glioblastoma.