TNFRSF17 and synovial sarcoma: Among the pathological mechanisms underlying SS, BAFF and BCMA are considered vitally important (Gross et al., 2000; Nocturne and Mariette, 2013; Vincent et al., 2013; Nezos et al., 2014), particularly in patients with advanced disease, given that BAFF-BCMA interaction may promote lymphocyte proliferation (Jiang et al., 2011; Cornec et al., 2012).