Differential miRNA expression in CD71⁺ erythroid cells by microarray and Q-PCR analysis. (A) Heatmap illustrates relative changes in miRNA expression of 10 miRNAs that were significantly different between CD71⁺ cells from 2 individuals without SCA (HbAA), 3 SCA patients before hydroxyurea (HbSS), and 3 SCA patients at hydroxyurea MTD (HbSS(H)). Significant changes were identified in this cross-sectional study by Z-score statistic where P < .05. (B) Graphs illustrate the change in expression of miRNAs 148a, 151-3p, and 494 from baseline to MTD for each patient (gray symbols and lines). Median miRNA expression was significantly higher at MTD compared with baseline for each miRNA as determined by the Wilcoxon signed rank test (*P = .03; **P = .0036; ***P = .0002).