CXCL12 and B-cell chronic lymphocytic leukemia: Taken together, while chemokine receptor regulation in response to stimulation with α-IgM and α-IgD was reduced in CLL, with compensation when using stronger BCR stimulation by immobilised antigens, differential regulation of CXCL12- and CCR7-mediated chemotaxis was observed after IgM and IgD activation.