The signal transduction pathways driven by BAFF and APRIL have not been fully elucidated, however, it has been shown that BAFF and APRIL constitute myeloma cell growth factors by activating pro-inflammatory signaling, such as NF-κB, MAP, and PI-3 kinase pathways, as well as by affecting the regulation of anti-apoptotic proteins (e.g., Bcl-2) [48]. Here, TNFSF13B is linked to plasma cell myeloma.