IDH1 and glioma: Although the World Health Organization (WHO) classification has incorporated molecular markers, such as isocitrate dehydrogenase (IDH) mutation, chromosome 1p/19q codeletion, and TERT promoter mutation, which has greatly improved the stratification of glioma patients (Louis et al., 2016), the heterogeneity of gliomas still needs to be further elucidated.