All 13 of these matched with IDH-mutant, non-1p/19q-codeleted astrocytoma; 3 of these were consistent with glioma CpG island methylation phenotype (G-CIMP) “low” and the remaining 10 were G-CIMP “high.”40,41. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).