Among the enzymes that catalyze the reactions coupled with the production of NADPH, THF dehydrogenases (cytosolic ALDH1L1 and mitochondrial ALDH1L2) and MTHF-dehydrogenases (mitochondria MTHFD2L and cytosolic MTHFD1) are involved in cancer. The gene discussed is ALDH1L1; the disease is cancer.