Flow cytometry analysis revealed that COPD patients (n = 35) presented greater numbers of activated circulating platelets (PAC-1+ and P-selectin+) expressing CXCL16 and CXCR6 as compared with age-matched controls (n = 17), with a higher number of CXCR6+-platelets in the smoking COPD group than in ex-smokers. Here, CXCL16 is linked to chronic obstructive pulmonary disease.