CXCR4 and B-cell chronic lymphocytic leukemia: CLL: chronic lymphocytic leukemia, CXCR4: C-X-C chemokine receptor 4, del(17p): deletion of the short arm of chromosome 17, IgHV: immunoglobulin heavy chain variable region, MYD88: myeloid differentiation primary response 88, TP53: tumor protein 53, WM: Waldenström macroglobulinemia