TTR and cardiac amyloidosis: The main types of cardiac amyloidosis are amyloid light chain (AL) amyloidosis caused by an underlying plasma cell dyscrasia, amyloid transthyretin (ATTR) amyloidosis of either non-mutant (wild-type) TTR seen at older age (ATTRwt) and hereditary or mutant TTR (ATTRm) amyloidosis in which a genetic mutation leads to an unstable transthyretin (TTR) protein [4].