Among "common" clusters, of particular clinical interest is a cluster composed by UM CLL with stereotyped BCR expressing genes from the IGHV1 gene family other than IGHV1-69 (IGHV1-2,IGHV1-18, IGHV1-3,IGHV1-46, IGHV7-4-1), homologous HCDR3 bearing the QWL amino acid motif, and IGKV1-39 light chains [89,91,92]. This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.