Iron deficiency diminished the differences of blood indices between WT and Fpn conditional KO mice. RBCs (A), hemoglobin (Hb) (B), HCTs (C), MCV (D), reticulocytes (Retic) (E), and MCH (F) of WT and Fpn KO mice after treatment with high-iron or low-iron diets for 3 months. There were significant differences between WT and Fpn KO mice on high-iron diets, whereas the differences between the 2 genotypes disappeared on low-iron diets for RBCs, hemoglobin, HCT, reticulocytes, and MCH. Mean ± 95% CI, statistical significance determined with 2-way analysis of variance and Sidak's multiple comparisons tests.