The characterization of hemojuvelin (HJV), the protein mutated in type 2A hemochromatosis [2], as Bone Morphogenetic Protein (BMP)-coreceptor, functionally linked the BMP-Sons of Mothers Against Decapentaplegic (SMAD) pathway to hepcidin and iron regulation [3]. The gene discussed is HJV; the disease is hemochromatosis type 2.