In comparison to Eμ-myc/17-92 mice, both Eμ-myc/17-92Δ92 and Eμ-myc/17-92Mut92 mice developed more aggressive B-lymphomas, characterized by massive lymph node enlargement, splenic hyperplasia, leukemia, and widespread dissemination into visceral organs outside of the lymphoid compartment (Figure 2B, data not shown). This evidence concerns the gene MYC and leukemia.