Increased Epo levels only in rats consuming the LFe/LCu and HFe/LCu diets suggests that copper deprivation increases Epo expression, independent of hypoxia or anemia, since some anemic, presumably hypoxic, rats (e.g. in the LFe/AdCu, LFe/HCu and HFe/AdCu groups) did not show such dramatic increases in Epo expression. This evidence concerns the gene EPO and anemia.