CD34 and breast cancer: We found that when CD34+ UCB cells were cultured in vitro for 4 days, there was a considerable increase in the proportions and absolute number of both the CD34+CD38− (HSPCs) population (Figure 4C,D) and CD34+CD38−CD45RA−CD90+ (HSCs) (Figure 4C,E) subpopulations upon BC treatment in comparison with the control group, but 10 μg/mL BC was more effective than 20 μg/mL.