Effects of the PI-3 kinase inhibitor, wortmannin, PKC inhibitor, GF109203X or MEK kinase inhibitor, PD98059 on SDF-1–induced migration of CD34⁺ marrow cells. CD34⁺ cells were treated with either carrier alone or various concentrations (shown in nanomolars) of wortmannin (Wort.), GF109203X (GF, μM}, or PD98059 (PD, μM) for 45 minutes. The cell migration in response to SDF-1α (20 nmol/L) or medium alone (random) was measured in a chemotactic assay as described in “Materials and methods.” Cell migration was shown as the percentage of cell input. The data shown represent the mean ± SD of 3 separate experiments. * and ** show statistical significance compared with control (cells pretreated with carrier, DMSO) and are assessed asP < .05 and P < .01, respectively.