SERPING1 and hereditary angioedema: In 2014 a comprehensive classification of “angioedema without wheals” was released, identifying three types of hereditary angioedema (genetic C1-INH deficiency, normal C1-INH with Factor XII mutations and unknown origin) and four types of acquired angioedema (C1-INH deficiency, related to ACE inhibitors intake, idiopathic histaminergic and idiopathic non-histaminergic) [1].