Among other anti-CXCR4 antibodies tested, 12G5 and 1D9, only 12G5 was able to induce cell death in CLL alone or co-cultured with stroma-NK-tert cells support, but the effect was weaker as compared to Ulocuplumab (BMS-936564). This evidence concerns the gene CXCR4 and B-cell chronic lymphocytic leukemia.