SERPING1 and angioedema: In these patients, angioedema typically responds to C1-INH infusion (Kaplan and Joseph, 2010; Schmaier, 2019; Bova et al., 2020; Busse and Christiansen, 2020; Lumry and Settipane, 2020; Valerieva and Longhurst, 2022), or drugs that neutralize PK/PKa or FXII/FXIIa (Cohn et al., 2020; Davoine et al., 2020; Busse and Kaplan, 2022), consistent with KKS hyperactivity as an underlying cause.