IDH1 and glioma: IDH1 (encoding a key enzyme in the TCA cycle, Isocitrate Dehydrogenase) is one of the most commonly altered metabolic genes across all studied cancer types [87], and its mutation is so robustly linked with glioma development and progression that this discovery has fuelled the initiation of a number of large-scale Phase I/II clinical trials targeting IDH1 in this disease setting [89].