GPD2 and thyroid cancer: Because mitochondria are intact in most non-oncocytic thyroid cancers, glycolytic thyroid cancer cells are also sensitive to inhibitors for mitochondrial function and biosynthesis, such as atovaquone (a complex III inhibitor) [69], tigecycline (an inhibitor of mitochondrial translation) [70], mitotane (a cytochrome c inhibitor) [71] and metformin (an inhibitor of complex I, mitochondrial glycerophosphate dehydrogenase (MGPDH), fructose 1,6-bisphopsphate and glucose-6-phosphatase [72,73,74].