Differential effects of IFN- priming on BCR/ABL expression in bone marrow mononuclear cell cultures from CML patients (A and B, IFN- responder patients; C, IFN-–resistant patient; D, a patient presenting in initial blastic transformation). Bone marrow mononuclear cells were cultured for 24 hours with the indicated concentrations (U/mL) of IFN-. Lower panels: Western blot for intracellular P210^BCR/ABLcontent, including P145^ABL determination used as an internal control.