We found that expression of the hamp gene in the kidney was increased in wild-type animals following provision of iron-loaded diet (Supplementary Figure 5E), but remained unaltered in hemochromatosis mice (Supplementary Figure 5D), and in those harboring renal tubule–specific loss of FPN or renal tubule–specific loss of HAMP responsiveness (Supplementary Figure S5F and G). The gene discussed is HAMP; the disease is hemochromatosis type 1.