Effect of growth factor stimulation on adhesion and transmigration of CFCs in peripheral blood CD34⁺-selected cells. (A) Percentage adhesion of GM-CFCs to HUVECs before (unstimulated) and after 3 days of growth factor stimulation (growth factor activated), mean ± SEM of five experiments. (B) Effect of growth factor stimulation (3 days) on transmigration of GM-CFCs and BFU-E across HUVECs (mean ± SEM of eight experiments). (C) Kinetics of growth factor-induced upregulation of GM-CFC migration across HUVECs, mean ± SEM of three experiments. (D) Transmigration of unstimulated, and 3-day growth factor-activated GM-CFs across BMECs and HUVECs. Data are the mean ± SEM of the percent migration of GM-CFCs in four paired experiments.