Proliferation from single CD34⁺CD38⁻ cord blood cells. (A) Timing of clonal appearance. Above the bars are shown the number of clones analyzed at each time point. (B) Relationship of timing of clonal appearance to generative capacity. Bars denote mean number of cells/clone ± SEM. Data for (A) and (B) are compiled from a total 130 clones initiated from 2,112 single CD34⁺CD38⁻ cells.