The IDH mutant glioblastoma could be further divided into G-CIMP-low, G-CIMP-high, and combined deletion (codel), while the IDH wild-type glioblastoma can be subdivided into classic-like, mesenchymal-like, LGm6-GBM, and pilocytic astrocytoma-like (PA-like) GBM. Here, IDH1 is linked to pilocytic astrocytoma.