TTR and cardiac amyloidosis: There are three main types of cardiac amyloidosis (CA): immunoglobulin light-chain (AL) amyloidosis, due to amyloidogenic monoclonal light-chain production by a plasma cell clone, hereditary transthyretin amyloidosis (ATTRv) caused by the deposition of mutated transthyretin (TTR), and wild-type (non-hereditary) TTR amyloidosis (ATTRwt) (2–5).