TRIM21 and synovial sarcoma: In terms of laboratory investigations, the positive rate of Anti-Ro/SSA antibodies in our cohort (94.4%) was slightly higher than what others reported (73.6%–82.7%), and the positive rates of other indicators such as Anti-La/SSB antibodies, ANA, RF, and IgG were not significantly different [5–8, 14–17], and the variation in these indicators was consistent with the features of SS.