Enzymes that generate NADPH at different locations in cell. ALDH1L1/2, aldehyde dehydrogenase 1 family member L1/2; G6PD, glucose-6-phosphate dehydrogenase; H6PD, hexose-6-phosphate dehydrogenase/glucose 1-dehydrogenase; IDH1/2, isocitrate dehydrogenase [NADP(+)]; ME1/3, malic enzyme 1/3; MTHFD1/1L, methylenetetrahydrofolate dehydrogenase cyclohydrolase and formyltetrahydrofolate synthetase 1; NADPH, nicotinamide adenine dinucleotide phosphate; NNT, nicotinamide nucleotide transhydrogenase; PGD, phosphogluconate dehydrogenase.