Clonality analyses in DNA of patient tissues and the U-RT1 cell line established. (A) The cell line represents the clone detected in the bone marrow specimen of the CLL. The gastric lymphoma and the lymph node tissue show differing clonal events. (B) Phylogram of the sequence comparison of amplicons produced by family-specific FR1 primer to amplify parts of the rearranged IGH locus. Products using VH2, VH3, VH4, and VH6 FR1 family primers were amplifiable and compared, indicating at least three clonal events that were independent of each other. CLL, chronic lymphocytic leukemia.