Bcr-Abl knockdown and dasatinib treatment of CML cells in physiologic growth factors. CD34⁺ CML cells were infected with sh-Bcr-Abl or sh-Control. (A) Forty-eight hours following second infection, cells were sorted for GFP and RNA, protein extracted, and relative expression of Bcr-Abl measured by Q-PCR (n = 5, P = .0004) and (B) Bcr-Abl and p-STAT5 by Western (n = 1). CD34⁺ non-CML (n = 3) and CML cells (n = 3) were cultured in SFM ± growth factors ± 150nM dasatinib. Twenty-four hours after treatment, (C) p-CrkL and (D) p-STAT5 were measured by flow cytometry. Lentivirally infected CD34⁺ cells (n = 3) were cultured in physiologic growth factors and treated ± 150nM dasatinib. Twenty-four hours after treatment, (E) p-CrkL and (F) p-STAT5 were measured in infected cells (gated on GFP) cells by flow cytometry.