Indeed, ectopic-GCs produce antibodies against citrullinated proteins in RA,10, 33, 34 ribonucleoproteins Ro/La in SS,35, 36 thyroglobulin and thyroperoxidase in Hashimoto's thyroiditis37 and acetylcholine receptor in myasthenia gravis.38 This evidence concerns the gene TPO and synovial sarcoma.