CpG-ODN + IL15-stimulated CLL cells were exposed to the drug for 2 days and then the percentage of proliferating cells, based on the number of cells in S, G2, and M phases of the cell cycle, and of recently divided cells, defined by CXCR4 and CD5, was evaluated. The gene discussed is CXCR4; the disease is B-cell chronic lymphocytic leukemia.