TNFSF13B and rheumatoid arthritis: Although the role of the BAFF pathway (BAFF/BAFF-R) has been deeply investigated in relation to several autoimmune diseases, such as rheumatoid arthritis (RA) [15] and systemic lupus erythematosus [16,17], data on primary Sjögren’s disease are mostly limited to soluble BAFF (sBAFF), and the possible correlation between its expression and lymphomagenesis in primary Sjögren’s disease remains to be elucidated.