SP1 and synovial sarcoma: These antibodies were later commercialized by Trinity Biotech under the name of “early SS autoantibody (eSjA) panel” and screened by their Immco Diagnostics Reference Lab. The panel includes three autoantibodies, namely salivary protein 1 (SP1), carbonic anhydrase IV (CA6), and parotid secretory protein (PSP), with three immunoglobulin isotypes (IgG, IgA, and IgM) for each antibody, totaling nine items.