These include various subtypes of GBM such as isocitrate dehydrogenase (IDH)-wildtype and IDH-mutant; diffuse midline glioma, H3 K27M-mutant; RELA fusion-positive ependymoma; medulloblastoma, WNT-activated and medulloblastoma, SHH-activated; and embryonal tumor with multilayered rosettes, C19MC-altered. The gene discussed is IDH2; the disease is diffuse midline glioma.