MSH2 and oligoastrocytoma: The MSH2 mutation-associated MMRD brain tumors included 43 gliomas, including GBM (n = 20), oligodendroglioma (n = 9), anaplastic oligodendroglioma (n = 6), diffuse astrocytoma (n = 5), anaplastic astrocytoma (n = 2), and oligoastrocytoma (n = 1).