CLL B-cell chemotaxis toward CXCL12 is PIK-90 and PI-103 sensitive. CLL cells were preincubated for 120 minutes with the reagents that are displayed on the horizontal axis before being assayed for chemotaxis toward 200 ng/mL CXCL12. Each bar represents the mean (± SEM) relative chemotaxis of B CLL cells from 5 different patients compared with untreated controls (100%). *Both concentrations of PIK-90 and PI-103 as well as pertussis toxin, used as a positive control, significantly inhibited chemotaxis to CXCL12.