CALR and synovial sarcoma: A key contributing factor in SS symptom development is the presence of abnormal B- and T-cell responses to the presence of the auto-antibodies SS-related antigen A and SS-related antigen B (anti-Ro/SSA and anti-La/SSB autoantibodies, respectively), which are detected in up to 90% and 60% of patients with SS, respectively [17].