In order to determine whether our assay was providing biologically meaningful measurements, we tested serum samples from patients with anticipated low hepcidin levels (HJV associated juvenile hemochromatosis and iron deficiency anemia) [4], [8], [16], [27], compared to healthy controls, as well as from patients with anticipated high hepcidin levels (Hodgkin's lymphoma with B-symptoms) [15], [28], [29], [30]. The gene discussed is HAMP; the disease is hemochromatosis type 2.