Recently an erythroid function for Tfr2 was independently reported by Wallace et al. (2013) who noticed that the triple knock-out (Tfr2-/-, Hfe-/-, Tmprss6-/-) mice have more severe iron deficiency than Tmprss6-/- mice with deletion of either Hfe or Tfr2. However, the mechanism underlining this difference remains to be worked out. The gene discussed is HFE; the disease is nutritional disorder.