IDH2 and astrocytoma (excluding glioblastoma): CNV, distributed across the entire genome, is significantly elevated in lower-grade IDH-mutant astrocytomas with rapid progression and short overall patient survival intervals relative to grade-matched IDH-mutant astrocytomas with more conventional clinical courses, and in many cases their copy number plots are indistinguishable from or demonstrate even greater intra-chromosomal gains and losses than WHO grade 4 IDH-mutant astrocytoma (Fig. 3) [94, 96, 98].