Among the 222 tumor samples, positive ETV2 expression was observed in 76.5% (62/81) of GBM and in 39.7% (56/141) of the low-grade brain tumor (astrocytoma, oligodendroglioma, and meningioma) but not in normal brain tissues (P < 0.0001, Fig. 2b). This evidence concerns the gene ETV2 and oligodendroglioma.