HAE is caused by pathogenic variants in SERPING1, leading to C1-inhibitor deficiency (HAE C1-INH), and in F12, ANGPT1, PLG, KNG1, MYOF, HS3ST6, DAB2IP, and CPN1, which are associated with HAE with normal C1-INH (HAE nC1-INH). The gene discussed is CPN1; the disease is hereditary angioedema.