FIGURE 1.

Regulation of systemic iron homeostasis by hepcidin. Enterocytes and monocytes release Fe²⁺ via the iron exporter ferroportin, which is then oxidized to Fe³⁺ and transported via the bloodstream. Liver-derived hepcidin inhibits iron efflux from these cells by binding to ferroportin, which promotes ferroportin internalization and degradation. The synthesis of hepcidin in the liver is induced by iron and inflammatory signals and suppressed by iron deficiency, anemia, or hypoxia.