We know that current therapies have a different impact in each compartment, where residual disease in lymph nodes poses a challenge to chemoimmunotherapy, and ibrutinib has been shown to mobilize CLL cells from lymph nodes to the circulation through the regulation of the chemokine receptor CXCR4 (36, 37). This evidence concerns the gene CXCR4 and B-cell chronic lymphocytic leukemia.