CCL2 and chronic obstructive pulmonary disease: In COPD, type M1 is more prevalent than M2, indicating a more accentuated inflammatory response [115], denoted by the release of pro-inflammatory mediators including CCL2 and CXCL1, which enhance cell recruitment, and explaining the higher number of macrophages found in the pulmonary parenchyma, BALF, and sputum of COPD patients [90,116].