With IDH-mutation having emerged as a major prognostic disease marker (18, 19, 46), the more favorable prognosis in IDH-mutated gliomas has been attributed to slower local tumor growth rates (46), to anatomical predelection sites that are more accessible to extensive tumor resection (47, 48), or to a less infiltrative nature of diffuse tumor cell migration (17). Here, IDH2 is linked to glioma.