TGFBI and rheumatoid arthritis: Transforming growth factor-β-inducible gene-h3 (βig-h3) is an ECM protein that consists of integrin-interacting structures, including four homologous fas-1 domains and an Arg-Gly-Asp (RGD) motif [6, 7], and is abundantly found within synovial tissues and fluid of RA [6, 8].