Amongst grade 2/3 IDH1/2-mutant astrocytomas in the non-TCGA cohort with available survival data, 8.9% of cases (20 of the 224) had a hemizygous loss of CDKN2A/B (Figure 1C) while 15.6% (19 of the 122) of grade 4 cases had a hemizygous loss of CDKN2A/B. The gene discussed is CDKN2A; the disease is astrocytoma (excluding glioblastoma).