SERPING1 and acquired angioedema: The acquired forms of angioedema (AAE) are classified into four types: AAE due to C1-INH deficiency (AAE-C1-INH) on acquired basis; AAE bradykinin-mediated (angiotensin converting enzyme inhibitor-induced angioedema, ACEI-AE); acquired forms related to mast cell mediators (urticarial angioedema, anaphylactic angioedema); and idiopathic angioedema [6].