Similarly, CLL cells failed to develop in the periphery, showing a rate of less than 2% as opposed to 30% in WT controls (Supplementary Figure 4C)); However, peritoneal TCL1-Tg BAFF-/- APRIL-/- CLL cells expanded in the peritoneal cavity to what was observed in TCL1-Tg BAFF-/- mice, albeit to a lesser extent than peritoneal CLL cells in TCL1-Tg controls (Supplementary Figure 4C; Figure 3A). This evidence concerns the gene TNFSF13 and B-cell chronic lymphocytic leukemia.