Based on the overall patterns of cytogenetic alterations and IGHV gene usage together with the BCR mutational status, it could be concluded that while some unmutated IGHV genes appear to be associated with the acquisition of complex cytogenetic profiles, rapid expansion of clonal CLL-like B-cells and progression to CLL (e.g. IGHV1-69), others would not (e.g. IGHV3-23); the latter clones would show a more benign behaviour. The gene discussed is BCR; the disease is B-cell chronic lymphocytic leukemia.