Adhesion of hematopoietic cells to endothelium. (A) Adhesion of neutrophils, monocytes, and CFCs in freshly isolated peripheral blood CD34⁺-selected cells to HUVECs. All adhesion assays were performed over 1 hour. Data are mean ± SEM of seven experiments with neutrophils, four with monocytes, and five with CD34⁺ selected cells. (B) Comparison of the adhesion of CFCs to BMECs and to HUVECs. Data are mean ± SEM of six paired experiments.