Of note, CD8+ T cells can act as a bridge between inhalation exposure and airway obstruction, with greater contributions than CD4+ T cells.[43] As the predominant T‐cell population in both airways and alveolar compartments of COPD patients,[44] CD8+ T cells drive airway remodeling and represent promising biomarkers for assessing airflow limitation and emphysema progression.[45]. This evidence concerns the gene CD4 and Airway obstruction.