CD5 and B-cell chronic lymphocytic leukemia: In line with this hypothesis, the IGHV1-69/IGHJ6 genes which show highly similar junctional regions to those of normal peripheral blood (PB) CD5+ GC B-cells are more frequently represented among U-CLL, supporting a close relationship between U-CLL cells and the B-cells responsible for the natural antibody repertoire (11).