As shown in Figure 2A, retrotranscription and amplification of the mRNAs encoding for IgM, IgG and IgA shows that B cells from Traf2DNxBCL2-tg+/+ mice with CLL/SLL almost exclusively express IgM, while all three Igs (M, G and A) mRNAs could be readily detected in B cells from representative mice of all the other genotypes. This evidence concerns the gene CD79A and B-cell chronic lymphocytic leukemia.