Additionally, in the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy—Not Official WHO (cIMPACT‐NOW) update 5, IDH‐mutant astrocytomas with CDKN2A/B homozygous deletion were classified into WHO grade 4 regardless of pathological findings.18 The gene discussed is IDH2; the disease is astrocytoma (excluding glioblastoma).