Complete Bcr-Abl inhibition is achieved by dasatinib within primitive subpopulations of CML cells. CFSE-stained CD34⁺ CML cells (n = 3) were cultured in SFM ± 150 or 1000nM dasatinib for 12 days. (A) The levels of total p-CrkL were measured by flow cytometry and (B) by Western blotting at day 12. p-CrkL was also measured within each cell division after treatment with either (C) 150 or (D) 1000nM dasatinib.