SMAD2 and synovial sarcoma: Sjögren’s syndrome (SS) is an autoimmune disease in which TGF-B/Smad2 signaling and matrix metalloproteinases are dysregulated, leading to hypofunction of salivary and lacrimal glands.66–68 Data from more than 13 000 patients with SS in a nationwide Longitudinal Health Insurance Database from 2000 to 2013 in Taiwan found an increased risk of developing BRONJ following tooth extraction compared with patients without SS (adjusted HR = 7.635, 95% CI 3.126–18.649, P < 0.001).