Flow cytometric analysis of Fas-R expression on CD34⁺ cells from a patient with CML stimulated with various concentrations of IFN-α. Total BM cells were cultured with or without IFN-α for 48 hours, stained with PE-conjugated CD34 and FITC-conjugated CD95 MoAb, and analyzed in the blast gate. (A) Without IFN-α; (B) IFN-α 500 U/mL; (C) IFN-α 1,000 U/mL. Gates were set based on isotypic controls.