In contrast, key regulators of OPC specification and maintenance [58], including MYT1, OLIG2, PDGFRA, PTPRZ1, SMOC1, and SOX8 were hypomethylated in PM gliomas (Fig. 6D, Additional file 1: Fig. S18 and Additional file 5: Table S4). The gene discussed is OLIG2; the disease is glioma.