Previous results showing iron overload in mice deficient in CD8+ T lymphocytes (de Sousa et al.1994x; Santos et al., 1996; Cardoso et al., 2002) and the inverse correlation recurrently observed between CD8+ T lymphocyte numbers and the severity of iron overload in HFE-HH human patients (Porto et al., 1997; Barton et al., 2005; Cruz et al., 2006) might thus need to be reinterpreted not as an indication that CD8+ T cells play a unique role in iron homeostasis but instead that the lack or a reduction in number of these cells affects the fine-tuning of iron homeostasis, namely NTBI distribution. The gene discussed is CD8A; the disease is Tangier disease.