MGMT and oligodendroglioma: Among 445 samples assessed via pyrosequencing, 217 (49%) tested positive for MGMT promoter methylation (101 IDHwt GBMs, 68 IDHmut astrocytomas, 48 IDHmut oligodendrogliomas), while 228 (51%) tested negative (200 IDHwt GBMs, 25 IDHmut astrocytomas, 3 IDHmut oligodendrogliomas).