Diffuse infiltrative low-grade gliomas (LGGs) are characterized as grade II or III astrocytoma and oligodendroglioma based on histopathological features and genotype including the status of the isocitrate dehydrogenase (IDH) mutation, 1p/19q codeletion and ATRX [1,2,3]. The gene discussed is IDH1; the disease is low grade glioma.