Effects of FL supplementation on total cell yields and the generation of CD1a⁺ cells. Ten thousand CD34⁺ CB cells were cultured for 10 days in serum-free medium in the presence of TGF-β1 plus GM-CSF, TNFα, and SCF as described in the Materials and Methods. Parallel cultures were further supplemented with FL. Bars represent mean values ± SEM of total cell numbers (left), percentages of cells positive (CD1a⁺ or LZ⁺/CD1a⁻; center), or total numbers of positive cells (right) observed in five experiments. The number of CD1a⁺ or LZ⁺/CD1a⁻ cells was calculated from the percentage of cells showing the respective phenotype multiplied by the total number of cells in each culture. (▪) −FL; (□) +FL.