IDH2 and diffuse midline glioma: PDHGG are classified into four types in the latest 5th edition of the WHO classification: diffuse midline glioma (DMG) H3 K27-altered, diffuse hemispheric glioma H3 G34-mutant, diffuse pediatric-type high-grade glioma H3-wildtype and IDH-wildtype, and infant-type hemispheric glioma [18].