Single-cell sequencing revealed four basic cell states in glioblastoma—neural progenitor-like (NPC), oligodendrocyte progenitor-like (OPC), astrocyte-like (AC), and mesenchymal-like (MES)—and three basic cell states for IDH-mutant gliomas: including astrocytic-like, oligodendrocyte-like and undifferentiated, stem cell-like [15,166]. Here, IDH2 is linked to central nervous system cancer.