IL17A and chronic obstructive pulmonary disease: IL‐17A has been found to facilitate neutrophil inflammation in COPD patients. COPD (18 cases, average age 72 years, 13 male, FEV1% = 63.5% [FEV1% is first second expiratory volume as a percentage of expiratory lung volume]) increased numerous IL‐17‐expressing inflammatory cells in the small airway epithelium compared to smokers and nonsmokers.29