TNFSF11 and B-cell chronic lymphocytic leukemia: Whereas all animals of the control group had to be euthanized 24 d after MEC-1 transplantation because of weight loss and hind limb paralysis due to infiltration of the MEC-1 cells into the spinal cord (Fig. 6 E), anti-RANKL treatment significantly extended the symptom-free survival for this aggressive, rapidly progressing human CLL xenograft model (Bertilaccio et al., 2013).