Diffuse gliomas are the most common type, especially in adults, and are characterized by alterations in the IDH gene; they include three types: IDH-mutant astrocytoma, IDH-mutant and 1p/19q-deleted oligodendroglioma, and IDH-wild-type glioblastoma. This evidence concerns the gene IDH2 and astrocytoma (excluding glioblastoma).