The patient diagnosed with a WHO grade II oligoastrocytoma would likely be diagnosed with a WHO grade II oligodendroglioma using current diagnostic criteria (particularly given the confirmed presence of a 1p19q codeletion; information about 1p19q, IDH, and ATRX status are provided in the Supplementary Results, including Supplementary Table S6). The gene discussed is ATRX; the disease is oligodendroglioma.