Carboxypeptidase N (CPN), angiotensin-converting enzyme (ACE), and aminopeptidase P (APP) are major kinases involved in kinin catabolism [64]. Drouet et al. investigated the kininase activity in C1-INH-HAE patients with and without androgen prophylaxis [65]. This evidence concerns the gene SERPING1 and hereditary angioedema.