MTHFD2 and cancer: Activation of mTORC1 stimulates de novo purine synthesis through control of the mt tetrahydrofolate cycle targeting methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) in serine-driven one-carbon metabolism which raises cellular NADPH/NADP+ and GSH/GSSG ratios to confer anabolic metabolic advantages for cancer metastasis [41,42].