TG and B-cell chronic lymphocytic leukemia: Another gene, VHJ558.b9 (IGHV1) is found in 15% of the Traf2DNxBCL2-tg+/+ CLL/SLL clones (13.3% of all Traf2DNxBCL2-tg+/+ B cell clones), a statistically significant difference (P<0.0001) compared to the 1.18% rearrangement frequency found in the C57BL/6 strain (33).