These effects of DPP IV inhibition on airway and other organ symptoms were predictable given the relationships between ACEI and cough, neutral endopeptidase (NEP, CD10; EC 3.24.11) with neurogenic inflammation, and complement C1 esterase inhibitor and hereditary angioneurotic edema [24,25]. The gene discussed is DPP4; the disease is hereditary angioedema.