FH and cancer: Indeed, mutations in either fumarate hydratase (FH) or succinate dehydrogenase (SDH B, C and D), both enzymes of the TCA cycle, are known to promote different cancer types, from leiomyoma, leiomyosarcoma and renal cell carcinoma (FH mutations) to paraganglioma and pheochromocytoma (SDH mutations) [19],[18].