The 2021 WHO glioma classification emphasizes the molecular markers isocitrate dehydrogenase (IDH), alpha-thalassemia mental retardation X-linked (ATRX), and codeletions of both the short arm of chromosome 1 (1p) and long arm of chromosome 19 (19q), or 1p19q codeletion, alongside traditional histology, to establish integrated diagnoses of astrocytoma, oligodendroglioma, or glioblastoma.1 This evidence concerns the gene ATRX and astrocytoma (excluding glioblastoma).