Because TMPRSS6 is a key modulator of hepcidin, down-regulating or inhibiting TMPRSS6 was first proposed as a therapeutic strategy to increase hepcidin levels in iron overload diseases such as hemochromatosis and β-thalassemia, two conditions for which TMPRSS6 has been validated as a pharmacological target [9–12]. The gene discussed is HAMP; the disease is Rare hereditary hemochromatosis.