CLL B cells overexpress chemokine receptors which guide lymphocyte homing to both nodal and extranodal sites, including CXCR4, CCR7, CXCR5, CXCR3 and CCR2 [52,81,82,83,84,86,87,88,89,90,91,92,93]. This evidence concerns the gene CXCR5 and B-cell chronic lymphocytic leukemia.