IRP1 deficiency leads to suppressed hepcidin expression in the liver, hyperferremia, and depletion of splenic macrophages from iron due to accumulation of ferroportin. WT, IRP1^−/−, and IRP2^−/− mice (n = 6) were euthanized at the age of 4 to 6 weeks. (A) Analysis of liver hepcidin mRNA expression by quantitative polymerase chain reaction. (B-D) Analysis of serum iron, transferrin (Tf) saturation, and serum ferritin levels. (E-F) Quantification of hepatic and splenic iron by the ferrozine assay. (G) Immunohistochemical detection of splenic ferroportin (FPN). (H) Assessment of splenic iron deposits by Perls’ Prussian blue staining. *P < .05; **P < .01.