Evidence of a delayed B/NM differentiation process in CD34⁺RA^–C^– cells exhibiting a slower cycling behavior. (A) Experimental design used to compare the changing output phenotypes generated from slow- and fast-cycling CD34⁺RA^–C^– cells. (B) Output numbers (mean ± SEM) of different progeny phenotypes generated from slow- and fast-cycling input CD34⁺RA^–C^– cells, determined at different time points (n = 3 experiments). Slow- and fast-cycling input cells were defined by their average cell cycle transit time of ≥48 or ≤24 hours, respectively. ∗P < .05 via pairwise t tests post Holm adjustment. (C) Experimental design used to examine and compare the clonal outputs of individual slow- and fast-cycling CD34⁺RA^–C^– cells. (D) Percentages of clonal output types produced from CD34⁺RA^–C^– input cells. Slow- and fast-cycling input cells were defined by their average cell cycle transit time of ≥48 or ≤24 hours, respectively. Each bar shows the mean ± SEM of values pooled from 4 different experiments in which a total of 540 and 520 single cells were assessed from the slow- and fast-cycling progenitors, respectively. Clone size (E) and the number of CD34⁺ output per clone (F) generated from individual slow- or fast-cycling progenitors. Clones (defined as ≥5 human cells) pooled from all experiments shown above were grouped by the lineage output type. “n.d.” represents signals below the limit of detection (5 cells). ∗P < .05 via pairwise t tests.