In addition, the diagnostic algorithm includes sequential tests: spirometric tests of airway obstruction, bronchodilator reversibility, verification of eosinophilic airway inflammation by measurement of IgE, sputum and blood eosinophils, and periostin, fractional exhaled nitric oxide (FeNO), and airflow variability and/or bronchial challenge (airway provocation) test or exercise challenge test [1]. The gene discussed is IGHE; the disease is Airway obstruction.