Expression of targeted antigens on different cell types. The expression of the 6 antigens targeted by antibodies was examined by flow cytometry. The expression on 2 skin keratinocyte cell lines (A-B), 1 AML cell line (C), and CD34⁺ circulation AML cells from 2 patients (D-E) is shown. Red indicates isotype control–PE; blue, anti-antigen–PE. Pt., patient.