CD133⁺ cells express functional adhesion molecules and CCR7 receptor. We evaluated the functionality of adhesion molecules expressed by CD133⁺ cells with in vitro adhesion assays on their ligands, and we tested the effect of chemokines on this binding (A). Unstimulated CD133⁺ cells adhered to human VCAM-1 in vitro. This binding was improved by stimulation with CCR7 ligand MIP3β. Only a reduced number of cells adhered to human ICAM-1, and a chemokine response to stimulation led to increased cell adhesion. Adhesion was completely absent in uncoated wells and extremely low in wells coated with FCS (background adhesion). Results are expressed as mean ± SD of adherent cells per 0.2 mm². The number of spontaneously adhered cells was compared with the number of cells that adhered after stimulation with CCL19 by using 2-tailed Student t test. ^*P < .01; ^**P < .001. The functionality of PSGL1 was evaluated with a cytofluorimetric assay; 40% of CD133⁺ cells were able to bind E-selectin, but only 10% were able to bind P-selectin (B). CD133^- showed very low ability to bind E- and P-selectin (1.1% ± 0.3% and 1.9% ± 0.2%, respectively) (C).