Six mutations in genes unrelated to C1-INH have been identified in HAEnC1 patients (Table 1, right column) that are assumed to be causative for, or contributory to, angioedema (Dewald and Bork, 2006; Bork et al., 2015; Bafunno et al., 2018; Dewald, 2018; Bork et al., 2019; Ariano et al., 2020; Bork et al., 2021; Veronez et al., 2021). The gene discussed is SERPING1; the disease is angioedema.