SERPING1 and hyperinsulinemic hypoglycemia, familial, 4: AE-BK occurs in hereditary AE (HAE) with or without C1INH deficiency (HAE-C1INH, e.g. HAE-PLG, HAE-FXII), acquired AE due to C1INH deficiency (AAE-C1INH), or AE-DI due to intake of drugs targeting the renin-angiotensin-aldosterone system (RAAS, i.e. AE-ACEI, AE-Sartan and AE-Gliptin, presumably BK-driven) (1).