HAMP and Tangier disease: As reviewed by Bartnikas et al., hepatocyte‐specific deficiency of the BMP type I receptor Alk2 and Hfe in mice leads to moderate iron overload compared to wildtype littermates,21 while in contrast, global or hepatocyte‐specific deficiency of Alk3, Hjv (hemojuvelin), and Hamp (hepcidin) are characterized by severe iron overload with up to five‐fold elevated liver iron content compared to controls due to severe depletion of hepcidin levels.21, 22, 23, 24, 25