GBMs were characterized as primarily TERT promoter mutant/IDH wildtype (73.3%), Grade II-III astrocytomas were predominantly TERT promoter wildtype/IDH mutant (73.9%), and the majority of oligodendrogliomas mainly harbored mutations in both the TERT promoter and IDH1/2 (79.3%). This evidence concerns the gene TERT and oligodendroglioma.