Minihepcidin peptide alone or in combination with an iron chelator improved anemia and splenomegaly in animals with β-thalassemia. Treatment with DFP alone (1.25 mg/mL of drinking water) was not associated with changes in hematological parameters such as Hb level (A), RBC number (B), and HCT concentration (C). Combination with minihepcidin M009 (2.625 mg/kg) led to significant improvement in anemia when compared with vehicle treatment, as indicated by increased Hb level, RBC number, and HCT concentration (A-C). Reticulocyte count (D) and spleen size (E) were both significantly reduced when animals received minihepcidin alone or in association with DFP, reflecting improved erythropoietic efficiency. Flow cytometry studies of BM and spleen erythroid populations from thalassemic animals that received minihepcidin alone or in combination with DFP demonstrated reduced levels of ROS formation (F). As in Figure 1F, we show here a representative example of ROS-positive cells (control and treated groups) in the fraction that represents mature RBCs. Parameters of erythrocyte damage such as red cell distribution width (RDW; G), hemichrome formation (as shown with TAU gel; H), and red cell morphology (Giemsa staining of peripheral blood smear; I) were improved in animals treated with minihepcidin alone or in combination with DFP (when compared with control groups and the standard [st] in panel H). Erythropoietin levels (Epo) were reduced in animals receiving M009 as a consequence of improved anemia (J). Results represent mean ± SD; ****P < .0001, ***P < .001, **P < .01, and *P < .05. Analysis was performed using one-way ANOVA with Tukey multiple comparison adjustment. WT data are displayed as a reference guide but are not included in the between-group test comparisons.