IDH1 and central nervous system cancer: Recently, the gene encoding isocitrate dehydrogenase-1 (IDH1), which converts isocitrate to α-ketoglutarate by oxidative decarboxylation, has been found to be mutated in up to 75% of grade II and III diffuse gliomas, and IDH1 mutations have been found to be a major prognostic marker for overall and progression-free survival in grade II–IV gliomas [4].