SERPING1 and hereditary angioedema: Historically, the available treatment options for HAE prophylaxis were limited to attenuated androgens such as danazol, antifibrinolytics such as tranexamic acid, and intravenously (IV) administered plasma-derived C1-INH (IV-C1-INH) replacement therapies such as Cinryze® (Takeda, Lexington, MA) [3, 12].