As understanding of the molecular basis of glioma has improved, in 2016 WHO combined traditional histopathology with diagnostic genetics (Nicholson and Fine, 2021), and for the first time incorporated the molecular features of IDH mutation and 1p/19q co-deletion into the diagnosis of glioma (Wesseling and Capper, 2018; Horbinski et al., 2022). Here, IDH1 is linked to glioma.