Outline of data analysis. (A) On the forward scatter (FSC) versus SSC display, cells in R1 were gated. (B) Gated cells in panel A were plotted on the CD45 versus CD34 display to gate CD34⁺ cells (R2). (C) Gated CD34⁺ cells were plotted on the CD45 versus SSC display (green dots) to identify stage I hematogones (CD34⁺CD10⁺CD19⁺ B-cell precursors [arrowhead]) and CD34⁺ myeloblasts (R3). Gray dots indicate other cells. The percentage of stage I hematogones in all CD34⁺ cells and the percentage of CD34⁺ myeloblasts in all nucleated cells was then determined. (D) Expression of various antigens on CD34⁺ myeloblasts gated in panel C was quantified by RMFI (MFI of each antigen staining divided by MFI of isotype-matched negative control staining).