CX3CR1 and chronic obstructive pulmonary disease: To gain an understanding of this difference, we first extended our previous finding that lung DCs in COPD have increased expression of markers of maturation and activation, including CD40, CD80, and CD86 (14), by examining CCR2, CCR7, and CX3CR1, which are chemokine receptors involved in DC maturation and trafficking (23–25).