BL-8040 (BKT140), a peptide inhibitor of CXCR4, has robust cell mobilization capacity [18, 19], similarly to other CXCR4-specific antagonist peptides (T-140, TN-14003, TC-14012), which were shown to inhibit CXCR4-CXCL12 signaling in CLL-B cells [4]. Here, CXCL12 is linked to B-cell chronic lymphocytic leukemia.