ETV2 and astrocytoma (excluding glioblastoma): As an initial step to test this hypothesis, we first investigated the expression of ETV2 in clinical brain tumor specimens, including glioblastoma (GBM grade III–IV, n = 81), astrocytoma (grade I–II, n = 86), meningioma (grade I–II, n = 48), and oligodendroglioma (grade I–II, n = 7).