When given subcutaneously, icatibant (Firazyr) aborts or limits attacks of hereditary angioedema (HAE) of type I and type II and attacks in patients with normal C1 inhibitor (HAE-nC1 INH) (Cicardi et al., 2014; Wu et al., 2016; Bouillet et al., 2016). This evidence concerns the gene SERPING1 and hereditary angioedema.