IDH3A and central nervous system cancer: Isocitrate dehydrogenase (IDH) mutations are present in 68% of lower-grade gliomas and play a key role in informing the treatment and prognosis of glioma patients.3 MT affects both IDH mutant and wild-type patients, at an estimated incidence of 45% in oligodendrogliomas and 74% of astrocytomas.4 Prior studies on MT were overwhelmingly conducted in patient cohorts of mixed IDH status.