SERPING1 and angioedema: The clinical safety and efficacy of C1‐INH(SC) were confirmed in the COMPACT (Clinical Study for Optimal Management of Preventing Angioedema with Low‐Volume Subcutaneous C1‐inhibitor Replacement Therapy) study, a randomized, placebo‐controlled, dose‐ranging, double‐blind, crossover trial designed to test the hypothesis that twice‐weekly administration of C1‐INH(SC) could reduce the frequency of HAE attacks compared with placebo (Longhurst et al., 2017).