A C1‐INH concentrate formulated for subcutaneous administration (C1‐INH[SC]; CSL830; HAEGARDA®; CSL Behring, Marburg, Germany) for the routine prevention of HAE attacks (Longhurst et al., 2017; Zuraw et al., 2015) was approved by the US FDA in 2017. Here, SERPING1 is linked to hereditary angioedema.