Interestingly, usage of the stereotypic VH11/Vκ14 BCR was significantly increased in CLL from IgH.TEμ.Cd40l−/− mice (n = 7/7, 100%), compared with control IgH.TEμ mice (n = 9/25, ~36%, Chi-square p < 0.001). This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.