<prompt> Protein implicated in Familial Amyloidosis isSerum amyloid Ab2-microglobulinAmyloid b peptideTransthyretin  <response>: A Classification of AmyloidosisTypeProtein ImplicatedPrimaryPrincipally light chains of immunoglobulinsSecondarySerum amyloid A SAAFamilialTransthyretin; also rarely apolipoprotein A-1,cystatin C, fibrinogen, gelsolin, lysozymeAlzheimers diseaseAmyloid b peptideDialysis-relatedb2-microglobulinRef: Harper;s Biochemistry; 30th edition; Chapter 52; Plasma Proteins Immunoglobulins; Table 52-7 