IDH2 and astrocytoma (excluding glioblastoma): These IDH-wildtype tumors can be stratified by copy number burden (using 10% as a threshold), although the vast majority of both histologic and molecular glioblastomas do not fit into this category [97], and CNV level alone is not as useful of a measure in IDH-wildtype compared to IDH-mutant astrocytomas (Fig. 2E).