Transthyretin (TTR) is a tetrameric transport protein highly conserved through vertebrate evolution and synthesized in the liver, choroid plexus, and retinal pigment epithelium. TTR transports the thyroid hormone thyroxine and the retinol-binding protein (RBP) bound to retinol (vitamin A). Mutations in TTR are associated with inherited transthyretin amyloidosis (ATTRv), a progressive, debilitating disease that ...