They then classified low-grade gliomas into following types: type I, with both IDH mutant and 1p19q codeletion; type II, with IDH mutant only; and type III, with wild-type IDH. Natsume et al. [21] also found that low-grade gliomas were composed of three subtypes, similar to TCGA's classification. Here, IDH1 is linked to glioma.