CD34⁺CD38⁺, CD34⁺CD38^+/−, and CD34⁺CD38⁻ cells were cultured with LAPSN retrovirus with either 4 HGF or 4 HGF + FLT3L. Cells were harvested after 2.5 days in the presence of retrovirus and total of 10 days culture in HGF. Cytocentrifuge preparations were stained for akaline phosphatase and the number of positive cells were expressed as a proportion of total cells. The figures in the table represent the percentage of alkaline phosphatase positive cells (number of positive/total cells examined).