The collected data suggested that the hub genes, including CCL2, IL13, MAPK14, and ALOX5, were mainly associated with phosphatidylinositol phospholipase C activity, G protein–coupled peptide receptor activity, and the positive regulation of cation channel activity, which are regulated by COPD drugs (Figures 3E,F). This evidence concerns the gene CCL2 and chronic obstructive pulmonary disease.