TTR and amyloidosis: However, patients with TTR amyloidosis do not show significant symptoms of thyroid hormone deficiency, suggesting that TTR may not be a major carrier of thyroid hormones and that reducing TTR expression may be a possible approach to treat this disease.298,301 The main clinical treatment options are liver transplantation and stabilization of tetramers with the small molecule tafamidis; however, the latter is not a stable and effective approach.31 The FDA has also approved the siRNA drug patisiran for the treatment of this disease.