In HAE-nC1INH, several mutations have been described in genes coding proteins targeting the kallikrein-kinin system, such as factor XII (6, 7), plasminogen (8) or kininogen (9) and the vascular endothelium, such as angiopoietin (10), myoferlin (11) and heparan sulfate-glucosamine 3-O-sulfotransferase 6 (12). The gene discussed is KNG1; the disease is hereditary angioedema.