The genes that cause HAE in patients with normal C1-INH levels are coagulation factor 12 gene (F12) (discovered in 2006) (Dewald and Bork, 2006), angiopoietin-1 (ANGPT1) and plasminogen gene (PLG) (discovered in 2018) (Bafunno et al., 2018; Bork et al., 2018b), and kininogen-1 gene (KNG1) (discovered in 2019) (Bork et al., 2019). Here, SERPING1 is linked to hereditary angioedema.