TNFSF13B and synovial sarcoma: It has been reported that activation of innate and adaptive immune pathways, including type I IFN pathway, TGF-β/SMAD/Snail signaling pathway, and B cell activating factor (BAFF)/BAFF receptor axis, plays a crucial role in the pathogenesis of SS (Mavragani, 2017; Sisto et al., 2018).