CXCL12 and B-cell chronic lymphocytic leukemia: Surprisingly, the normal B cells showed a significantly greater (p<0.0001) ability to migrate to CXCL12, with respect to both efficacy (4.5+/−1.2% migration in normal vs. 0.85+/−0.48% migration in CLL cells) and potency (∼10 nM in normal vs ∼50 nM in CLL cells) (Figure 2).