Anti-hepcidin therapy in iron-restricted anemias. (A) The hormone hepcidin is produced by the liver and controls the flow of iron into plasma from enterocytes that absorb dietary iron, from macrophages of the spleen and liver that recycle old red blood cells (RBCs), and from hepatocytes that store iron. In inflammation and several other conditions, hepcidin production is elevated. This causes iron restriction and contributes to the development of anemia. (B) Neutralization of hepcidin by anti-hepcidin antibodies increases plasma iron levels and improves anemia. Anti-hepcidin therapeutics alone or in combination with existing therapies for iron-restricted anemias (erythropoiesis-stimulating agents [ESAs] and intravenous iron) may allow safer and more effective treatment of anemia. Fe-Tf, iron-transferrin.