Hemoglobin, spleen index, mean corpuscular volume, and reticulocytes distribution width in WT and thalassemic mice from 3 to 12 weeks of age. Hemoglobin concentration (A) was low in Th3/+ mice and unchanged by manipulation of Erfe. Erfe^−/−, Th3/+ had reduced spleen index compared with Th3/+ mice at 6 and 12 weeks of age (B). Erfe^+/−, Th3/+ mice also had slightly lower spleen index than Th3/+ mice at the age of 12 weeks. MCV (C) and RDW (D) were significantly reduced in Erfe^−/−, Th3/+ mice compared with Th3/+ mice at the age of 6 and 12 weeks. No difference was observed at 3 weeks of age. Data shown are means ± SEM and were compared for each age between Erfe^−/−, Th3/+ or Erfe^+/−, Th3/+ mice and Th3/+ mice (n = 9-36 per group) by 2-tailed Student t-test. ***P < .001, **P < .01, *P < .05. For comparison, hemoglobin and spleen index were respectively higher and lower in WT mice compared with all the thalassemic mice (#P < .001). MCV was higher at the age of 12 weeks, and RDW was lower at all ages in WT compared with all the thalassemic mice (#P < .001). Note that the data in A and C for 6-week-old WT, Th3/+, and Erfe^−/−, Th3/+ mice were previously shown in Figure 15B and 15C, respectively, of Kautz et al.¹²