As previously demonstrated [13], the small GTPase RhoA plays a critical and conserved role in the CXCL12-induced inside-out signaling leading to LFA-1 affinity up regulation in CLL B-lymphocytes, but the mechanism of RhoA activation by CXCL12 in B-CLL is unknown. The gene discussed is CXCL12; the disease is B-cell chronic lymphocytic leukemia.