Flow cytometric analyses of CFP transgene expression after prolonged ex vivo culture. (A-C) Shown are dot plot analyses of MFGS-CFP–transduced normal CD34⁺ PBSCs on different days. (Day 9 of ex vivo culture for the same sample is shown in Figure 2B). (D) Cells sorted for CFP transgene expression on day 15 maintain CFP expression. The percentage of CFP-positive cells is indicated for each plot.