At the protein level, genetically predicted TNFAIP3 (OR 2.47, 95% CI 1.56–3.92) was positively associated with SS risk, while BTN3A1 (OR 2.96E-03, 95% CI 2.63E-04–3.33E-02) was negatively associated with SS risk. Here, BTN3A1 is linked to synovial sarcoma.