SERPING1 and hereditary angioedema: HAE can be classified into three types on the basis of the underlying pathogenesis: deficient C1INH (HAE-C1INH Type 1, HAE Type 1), dysfunctional C1INH (HAE-C1INH Type 2, HAE Type 2), and normal C1INH (HAE-nC1INH, HAE Type 3) [5].