HAMP and infection: When the iron load increases (such as high iron reserve level, high serum iron)25 or in cases of infection and chronic inflammation,26 elevated hepcidin directly binds to membrane FPN, promoting its internalization as well as degradation in epithelial cells of intestinal, thereby inhibiting iron absorption into the blood.27 Under hypoxic conditions, intervened by hypoxia-inducible factor (HIF), there is a reduction in hepcidin expression, which promotes iron release.28