IDH1 and glioma: Finally, pediatric-type high-grade diffuse gliomas include diffuse midline glioma H3 K27-altered (grade 4), diffuse hemispheric glioma H3 G34-mutant (grade 4), diffuse pediatric-type high-grade glioma H3 and IDH-wildtype (grade 4), and infant-type hemispheric glioma (no definite grade assigned by the WHO 2021) [2].