In most patients studied, BAFF-myc binds to at least 25% of the leukemia cells (Figure 4B; mean 31.1%, range 0.8–92.9%), whereas binding of recombinant APRIL seems to be less pronounced (Figure 4B; mean 15.76%, range 0.8–55.3%). Here, TNFSF13B is linked to leukemia.