However, in a double-blind, parallel group, multicenter randomized placebo-controlled trial of adult patients with ACE inhibitor-induced angioedema with airway obstruction, patients were randomized 1:1 for single doses of either C1INH or placebo (0.9% NaCl) intravenously, in addition to standard care. The gene discussed is SERPING1; the disease is Airway obstruction.