It has been described that stromal cells in the lymphoid niche secrete chemokines such as CXCL12 and CXCL13, which bind to their corresponding receptors on CLL cells (CXCR4 and CXCR5), resulting in leukemic cell chemotaxis towards the lymphoid niche [22]. Here, CXCL12 is linked to B-cell chronic lymphocytic leukemia.