CCL2 and chronic obstructive pulmonary disease: Changes typically observed in COPD, such as the populations of WBC and neutrophils in BALF, the level of IgE in serum, morphological changes, the DNA levels, and the protein expression of cytokines and chemokines (TGF-β, CCL-2, CXCL1, and CXCL11) in the pulmonary system, were evaluated.