Significantly impaired CXCL12 and CXCL13-directed migration of Eμ-TCL1Tg;Rhoh−/−CLL cells. Percent migration of B220+ B cells or CD3−/CD5+/IgM+CLL cells after 4 hours in response to (A-B) CXCL12 and (C) CXCL13 in the absence (A-C) or presence (B) of 40 ug/mL ICAM-1. Shown is 1 representative experiment of 2 giving similar results. Data show mean ± SEM of triplicate wells (WT versus Rhoh−/−; *P < .05 and **P < .005, Student t test, n = 3).