Rescue of erythroid lineage deficiencies by transgene expression of SCF^X9/D3 (MR) in Sl/Sl^17Hmice. A comparison of (A) hematocrit levels and (B) peripheral RBC counts between Sl/+, Sl/Sl^17H, andSl/Sl^17H-MR mice. A minimum of 5 Sl/+, 3Sl/Sl^17H, and 6 Sl/Sl^17H-MR mice were examined in each group. Results show the mean ± SEM. *P < .05.