Serum and liver iron increased in Fe (serum iron; P < 0.0001, liver iron; P = 0.0071) and WD + Fe groups (serum iron; P = 0.0003, liver iron; P = 0.0262) compared with Cont group (Fig. 3a, b), associated with an upregulation of hepatic hepcidin (P < 0.0001 for Fe and WD + Fe vs. Cont) (Fig. 3d), the master regulator of systemic iron homeostasis8,25. Here, HAMP is linked to Wilson disease.