Kinetics in pro-B cell production from Pu.1 siRNA-treated CD34+ EB cells, and a comparison of the potential for pro-B cell development of these cells from different EB ages. (A) After Pu.1 siRNA treatment, in day 1, <5% of cells are pro-B cells; in day 2, it increased to ≈20%; on day 3, the percentage of pro-B cells has increased to 60–70%; then the percentage of pro-B cells gradually increased until day 5 (solid line, cells cultured with mSCF; dotted line, cells cultured with mGM-CSF and mIL-3). (B) CD34+ EB cells from different age EBs have similar potential in pro-B cell development under the Pu.1 siRNA treatment.