Astrocytoma was subdivided into grades 2–4 or not otherwise specified (NOS), consisting of diffuse astrocytoma, IDH-mutant (6 in grade 4, 22 in grade 2, and 14 in NOS), anaplastic astrocytoma, IDH-mutant (7 in grade 4, 5 in grade 3, and 4 in NOS), and glioblastoma, IDH-mutant (20 in grade 4) defined according to the previous classification. The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).