Although measurement of blood lymphocyte subsets was beyond the scope of the present study, it has been reported that proportions of the two major peripheral T-lymphocyte subsets expressed as CD4/CD8 ratio are stable before and after phlebotomy therapy for hemochromatosis, confirming the existence of a homeostatic mechanism that regulates the relative numbers of the two major blood T-lymphocyte populations [22,23]. The gene discussed is CD4; the disease is hemochromatosis type 1.