There are two main groups of IDH1/2 mutant gliomas: (i) astrocytomas exhibiting ATRX mutation, TP53 mutation and ALT activation, (ii) oligodendrogliomas harboring 1p/19q codeletion and hTERT promoter mutation with hTERT overexpression. Here, GPT is linked to astrocytoma (excluding glioblastoma).