IDH1 and oligodendroglioma: High-grade gliomas (HGGs) include the World Health Organization (WHO) grade 3 and 4 tumors and consist of astrocytoma (IDH-mutant), oligodendroglioma (IDH-mutant and 1p/19q-codeleted), glioblastoma (IDH-wildtype), diffuse hemispheric glioma (H3 G34-mutant and H3 K27-mutant), among other gliomas (Louis et al., 2021).