Dose-response curve of daunorubicin (A) and idarubicin (B). In a single-cell clonogenic assay, RhoD CD34⁺ cells before and after prestimulation in vitro with HGFs for 48 hours were exposed to increasing concentrations of anthracycline. Proliferation was expressed as the percentage colonies (>50 cells/well) in medium A with daunorubicin/idarubicin compared with the control (medium A without daunorubicin/idarubicin). The IC50s of daunorubicin (A) and idarubicin (B) of RhoD cells were 0.006 μg/mL and 0.006 μg/mL before and 0.004 μg/mL and 0.003 μg/mL, respectively, after proliferation induction.