Recent molecular characterisation of paediatric high grade gliomas [1,2,3] led to the World Health Organisation (WHO) redefining central nervous system (CNS) diagnostic criteria and diffuse gliomas (including DIPG) were reclassified into more precise entities including ‘DMG, H3 K27M-mutant’, ‘Glioblastoma (GBM), IDH1-mutant’ and ‘GBM, IDH1-wildtype’ [4,5]. The gene discussed is IDH1; the disease is diffuse intrinsic pontine glioma.