Flow cytometry analysis of BAL cells showed that melatonin treatments decreased the percentage of CD86+ AMs and CD86+CD206+ AMs in IAV/H3N2-infected COPD mice (Fig. 3a-e), indicating the decreased proportion of CD86+/CD206+ double-positive cells was largely attributed to the decreased expression of CD86 in CD206+ AMs. Here, CD86 is linked to chronic obstructive pulmonary disease.