Flow cytometric analysis of HbF synthesis in circulating RN-1–treated RBCs. (A) Whole blood from SCD mice was stained with anti-human HbF antibody. The number in the rectangle of each representative sample shows the percentage of HbF-high cells within the total. (B) Statistical analysis of the percentage of HbF-high cells by flow cytometry averaged over all samples. Statistically significant differences between RN-1–treated and untreated SCD mice are indicated (*P < .05; **P < .01). Bar graph data are presented as the mean ± SD (n = 4-6 mice per group).