TNFRSF11A and B-cell chronic lymphocytic leukemia: To this end, we first studied RANK receptor expression on CLL cells from TCL1 transgenic mice (Bichi et al., 2002) and found that these malignant cells expressed high levels of RANK on their surface, with a mean 10-fold increase compared with peripheral wt CD19+ B cells from littermate control mice (Fig. 6 A).