IDH1 and astrocytoma (excluding glioblastoma): Amongst IDH1/2-mutant astrocytoma in the non-TCGA cohort, CDKN2A/B loss (hemizygous or homozygous) was the strongest negative prognostic feature (HR: 2.81, 95%CI: 1.8–4.4) after adjusting for demographic, molecular, and treatment variables (Figure 1B, Supplementary Material 3).