IDH1 and diffuse midline glioma: pHGGs can be classified in molecular subgroups based on IDH and histone H3 mutations, including IDH-wildtype, IDH-mutant, H3.3/H3.1 K27-mutant diffuse midline glioma (DMG; also known as diffuse intrinsic pontine glioma or DIPG), and H3.3G34R/V-mutant gliomas (80).