While multiple tumors contained cells that express genes associated with more mature oligodendrocytes, the tumor PJ018 contained a well-defined subpopulation that strongly resembled myelinating oligodendrocytes with specific expression of multiple myelin genes including MBP, MOG, and MAG. Hence, HGGs harbor cells that resemble a broad spectrum of glial developmental states and maturities. Here, MAG is linked to neoplasm.