Some studies have suggested that the increase of CD8+ T cells is a negative factor for COPD patients, and even in some studies, it has been suggested that the application of small dose of azithromycin can reduce the number of CD8+ T cells in the alveolar lavage fluid of COPD patients, reduce the level of granulosin B released by CD8+ T cells in the peripheral blood, and improve the cellular immunity of COPD patients [30]. Here, CD8A is linked to chronic obstructive pulmonary disease.