Ten patients assigned to HAEnC1-INH did not have previously detected gene mutations, such as SERPING1, F12, ANGPT1, PLG, and KNG1. 1,4, 5, 6, 7 These patients had a family history of angioedema; thus, they were subclassified as HAE-unknown (Supplementary Table 2). Here, PLG is linked to angioedema.