SERPING1 and hereditary angioedema: Despite the well described pathophysiological role of the KKS and the multitude of approved treatments for HAE-C1INH, the search for novel biomarkers (3) remains in order to elucidate further biological consequences of excess KKS activation, develop improved therapies, and reduce diagnosis time for patients, which for many patients can take 4–9 years on average (4), if the identified biomarkers can be developed as diagnostic assays.