CLL lymphocytes express a restricted set of BCR due to non-random usage of gene families coding for the variable portion of the Ig.11 Furthermore, some CLL cases express highly homogeneous sequences of the heavy chain complementarity determining region 3 (HCDR3), a phenomenon referred to as “stereotyped” BCR18 that was shown to occur in up to one-third of the cases.19–21. This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.