Though BAFF’s highest binding affinity is with the B-cell receptor variants, TNFRSF13B/C, there have been reported in vivo cases where myeloma cells aberrantly express these receptors in addition to the normal plasma cell variant, TNFRSF17, further increasing the sensitivity of myeloma cells to BAFF secretion47. The gene discussed is TNFSF13B; the disease is plasma cell myeloma.