Importantly, it is found that BCRs on CLL cells from different patients can be virtually identical with respect to IGHV genes and sequences, indicating a potential common mechanism of disease pathogenesis in CLL involving a B cell populations with limited BCR heterogeneity and/or selection of the malignant clone by a limited set of antigenic determinants5,6. This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.