Adult-type diffuse gliomas include astrocytoma, IDH-mutant, oligodendroglioma, IDH-mutant and 1p/19q-codeleted and glioblastoma, IDH-wildtype whereas four tumor types are recorded in the group of pediatric-type diffuse LGG: diffuse astrocytoma, MYB or MYBL-altered, angiocentric glioma, polymorphous low-grade neuroepithelial tumor of the young (PLNTY) and diffuse LGG, Mitogen-Activated Protein Kinase (MAPK) pathway-altered [21]. Here, IDH1 is linked to astrocytoma (excluding glioblastoma).