Sites of action of novel treatments for GO. BAFF, B cell-activating factor; GAGs, glycosaminoglycans; GO, Graves' orbitopathy; IGF-1R, insulin-like growth factor 1 receptor; IL-6R, interleukin 6 receptor; MAb, monoclonal antibody; TNFα, tumor necrosis factor α TSH-R, thyrotropin receptor; TSI, thyroid-stimulating immunoglobulin.