Effect of FG-4497 on hepatic Hepcidin mRNA level in P4h-tm null, Hif-p4h-2 hypomorphic, and Hif-p4h-3 null mice. The P4h-tm^−/− (A), Hif-p4h-2^gt/gt (B), and Hif-p4h-3^−/− (C) mice and wild-type mice received 3 oral doses of FG-4497 (100 mg/kg) per week for (B) 3 or (A-C) 5 weeks and were killed 6 hours after the last dose. Statistical significance is shown for comparisons between the values for the vehicle-treated and FG-4497–treated wild-type mice, the means of the former being taken as 100%, and for comparisons between the FG-4497–treated gene-modified and wild-type mice (*P < .05, ***P < .0001). There are no significant differences between the values for the vehicle-treated gene-modified and wild-type mice in panels A through C. Values of n as in Figure 3. Error bars represent SEM.