To find out whether the reported down-regulation of liver hepcidin mRNA levels in mice could be reproduced and inversely related to the induction of HIF target genes, Balb/c mice on a normal (iron-rich) diet were exposed for 6–8 h to hypoxia (8% O2, Figure 9A–B) or 0.1% carbon monoxide (CO, Figure 9B), which leads to functional anemia and HIF activation. This evidence concerns the gene HAMP and anemia (phenotype).