TTR and amyloidosis: hATTR amyloidosis is caused by a genetic mutation in the transthyretin (TTR) gene that leads to misfolding of TTR proteins, aggregation of these TTR proteins into amyloid fibrils, and accumulation of these amyloid fibrils in multiple tissues and organs throughout the body, affecting the nerves, the heart, eyes, and the gastrointestinal tract [12–17].