Bradykinin-mediated pathways involve this vasoactive nonapeptide that activates endothelial cells.5,14,37 Several systems regulate bradykinin, including the coagulation, complement, and contact pathways.4,38 Excess bradykinin is due to production, release, or inhibition of its breakdown.39–41 This form comprises drug-induced angioedema (ie, ACEi-mediated), HAE types I and II, and several forms of acquired and idiopathic angioedema.13,20,42,43. Here, KNG1 is linked to angioedema.