For example, the expression of the adhesion molecule ICAM-1 is increased in the bronchial epithelium in mild/moderate stable COPD in comparison with both control nonsmokers and current smokers [15, 87] and may play a role in the T cell epithelial adhesion [15] and T cell-mediated response to viral infections [15, 88]. Here, ICAM1 is linked to viral infectious disease.