Increasingly recognized as a significant cause of heart failure, particularly in the elderly, CA is caused in the majority of cases by misfolded monoclonal immunoglobulin light chains from a clonal plasma cells process (AL amyloidosis) or misfolded TTR, a liver-synthesized protein that is normally involved in the transportation of the hormone thyroxine and retinol-binding protein (ATTR)14. This evidence concerns the gene TTR and AL amyloidosis.