✔ Can mast cell degranulation triggers influence the initiation of bradykinin-dependent angioedema, in particular HAE-C1-INH? ✔ Does bradykinin play a role in anaphylaxis with associated upper airway angioedema? ✔ Does individual mast cells localisation in the patient’s body correlate with the localisation of HAE-C1-INH attacks? ✔ Are mast cell-dependent diseases relevant to the course of HAE-C1-INH? The gene discussed is SERPING1; the disease is hereditary angioedema.