Earlier investigations have demonstrated glutamate reduction in IDH-mutagenized cell lines [34], surgically-derived IDH+ tumor samples [35, 36], and high-grade IDH+ lesions (7 T MRS) [37] compared to non-mutated counterparts, perhaps as a consequence of conversion to 2HG-precursor alpha-ketoglutarate via glutamate dehydrogenase [36, 38]. The gene discussed is IDH2; the disease is neoplasm.