In vitro data showing CYB5R3 KO in CD34⁺ HSCs lessens the F cell response to HU treatment. (A) Experimental design for CD34⁺ HSC study. (B-C) Western blot and quantification of CYB5R3 protein on day 15, analyzed by Mann-Whitney nonparametric test. (D-E) Representative flow plots and quantification showing the percentage of HbF⁺ cells on day 18 in the HU^neg and HU^pos groups, analyzed by 2-way ANOVA. (F-G) Representative flow plots and quantification showing the percentage of CD44_lowFSC_low populations on day 18 in the HU^neg and HU^pos groups, analyzed by 2-way ANOVA. (H) HU^pos/HU^neg ratio of the CD44_lowFSC_low population in NT control and KO cells, analyzed by Mann-Whitney nonparametric test. Data are expressed as mean ± standard error of the mean. A value of P < .05 was considered significant. SSC, side scatter; FSC, forward scatter; HU^neg, HU untreated; HU^pos, HU treated. Fluorochromes: HbF-APC, CD44-PE-Cy7.