The lower level of staining of CLL111 cells could be explained by IGLV3-21 being diluted by a second productive L chain rearrangement found in these CLL cells (IGKV3-20*01 F/IGKJ1*01 F) expressed by the vast majority of cells (Table 1, Figure 3B and data not shown), reducing the level of VL and VH/VL determinants on these cells.All CLL cells tested expressed low but comparable levels of surface Ig (data not shown). This evidence concerns the gene MLC1 and B-cell chronic lymphocytic leukemia.