Rare molecular subclasses were identified in 11 patients, including diffuse astrocytoma, MYB or MYBL1‐altered; diffuse glioneuronal tumour with oligodendroglioma‐like features and nuclear clusters (DGONC); diffuse glioneuronal tumour, subtype A; diffuse midline glioma, H3K27‐altered, subtype EGFR‐altered or H3K27‐mutant or EZHIP expressing; diffuse paediatric‐type high‐grade glioma, MYCN subtype; neuroepithelial tumour, PLAGL1‐fused; and rosette‐forming glioneuronal tumour. This evidence concerns the gene MYBL1 and diffuse astrocytoma.