The high-grade pediatric diffuse gliomas include four tumor types, three of which are new, where age and location are important criteria: diffuse midline glioma with H3 K27 alteration, diffuse hemispherical glioma H3 G34-mutated, high-grade pediatric diffuse glioma H3 and IDH wildtype, and, finally, the infantile hemispherical glioma. This evidence concerns the gene IDH1 and neoplasm.