This effect might be relevant considering that regional differences in the brain uptake of 59Fe–NTBI versus 59Fe–TfR have been reported (Deane et al., 2004), and that 59Fe–NTBI seems to be transported faster than 59Fe–TfR into the brain parenchyma of iron-overloaded disease-free mice. This evidence concerns the gene TFRC and Rare hereditary hemochromatosis.