Amyloid of as yet unknown fibril type is also common in explanted cardiac valves.41,42 Systemic AA amyloidosis complicating chronic inflammatory diseases, in which the amyloid fibrils are derived from the acute-phase reactant serum amyloid A protein, involves the heart in about 2% of cases with systemic AA amyloidosis. Here, SAA1 is linked to AA amyloidosis.