Which of the following is downregulated by Hepcidin?

Regulates iron absorption. It is synthesized & released by the liver in response to increase in intrahepatic iron levels. When the body is replete with iron, Hepcidin levels increase & inhibit iron transfer from enterocyte to plasma by binding to ferropoin. It also suppresses iron release from macrophages, which is an impoant source of the iron used by erythroid precursors to make hemoglobin.