Other diagnostic tools were also performed to investigate the amyloidosis subtype: screening for monoclonal gammopathy (97%, n = 139; FLC unavailable in 55% of them), Tc-PYP scintigraphy in patients with cardiac involvement (18%, n = 19), and assessment of serum amyloid A protein (SAA) levels in patients with suspected AA subtype (67%, n = 8). Here, SAA1 is linked to monoclonal gammopathy.