Although it cannot be excluded that a slight upregulation of the Cybrd1, Slc39a4, and Muc3 messengers also exists in Hfe-/- B6 mice but does not reach a level detectable by microarray or RT-PCR analysis, the differential expression of these genes between Hfe-/- D2 and B6 mice does not appear to be related to the individual capacity of the two strains to respond to an iron-deficiency signal. The gene discussed is SLC39A4; the disease is nutritional disorder.