In order to relate genomic results to severity of hemochromatosis, we first identified 210 genes exhibiting differences in basal expression between strains or with expression regulation in response to Hfe disruption, which reside within the five Hfe-modifier regions that we previously mapped on chromosomes 3, 7, 8, 11, and 12 [10]. The gene discussed is HFE; the disease is hemochromatosis type 1.