PRTN3 and synovial sarcoma: There are limited data available in the literature regarding the characteristics of patients with RA and SS [8]; however, the data reported here are supported by a smaller cross-sectional study of 85 patients with RA which showed that patients with RA with SS were more likely to be female and have longer disease duration and higher frequency of RF and/or anti-citrullinated protein antibody (ACPA) positivity [8].