Functional characterization of steady-state BM CD34⁺ cells isolated in subcompartments of G₀ /G₁ phase. (A) Progenitor cell assay. The number of hematopoietic colonies are given per 100 cells plated. Data shown above are the mean ± SEM of three experiments performed in duplicate. BFU-E, burst-forming unit–erythroid; CFU-GM, colony-forming unit–granulocyte/macrophage; CFU-MIX, CFU-mixed. *P < .05 v G_1a , G_1b , and G_1c CD34⁺ cells; **P < .05 v G_1a and G_1b CD34⁺ cells. (B) LTHC-IC assay. Frequencies are given per 100 cells as the mean ± SEM, n = 4. ***P < .05 v G_1b and G_1c CD34⁺ cells. Statistical analysis was made by ANOVA followed by SNK pairwise comparisons.