Similar to human CLL cells (21, 22), CLL cells in TCL1-Tg mice expressed BAFF-R, BCMA and TACI with notably higher TACI and lower BCMA cell surface expression relative to CD5+CD19+ B1 B cells in WT mice (Figure 1B). The gene discussed is TNFRSF13B; the disease is B-cell chronic lymphocytic leukemia.