CXCR5 and B-cell chronic lymphocytic leukemia: Using the Eμ-Tcl1 mouse model of CLL, Heinig et al. demonstrated that CXCR5 depletion reduces Eμ-Tcl1 leukemogenesis, CLL proliferation and that this chemokine is indispensable for the recruitment of CLL cells into the germinal center since CXCR5-defective cells localized in the marginal zone of the B-cell follicle (10).