IDH2 and glioblastoma: Based on evolutionary modeling using primary-recurrent tumor pairs and multisector tumor sampling, several independent groups have found that + 7/− 10 is homogeneous and longitudinally preserved and thus likely the first and glioma initiation event in a large fraction of IDH-wildtype diffuse astrocytomas/glioblastomas [69, 107, 168, 198, 229].