In a study performed with bronchial biopsies [89] from both AERD and AT asthmatic patients and control subjects, the authors reported that, compared with AT, patients with AERD have increased bronchial mucosal neutrophil and eosinophil numbers but reduced percentages of T cells, macrophages, mast cells and neutrophils expressing EP2. The gene discussed is PTGER2; the disease is ataxia telangiectasia.