In lung tissues of ILD patients, MCP-1 is expressed in epithelial cells, macrophages and vascular endothelial cells; MCP-1 is involved in inflammation and fibrosis response in the process of pulmonary fibrosis by recruiting and activating monocytes and lymphocytes, and is also involved in the extracellular matrix deposition and changes in normal lung structure by promoting the proliferation of desmocytes, the secretion of collagen and the production of fibrosis-promoting cytokines, which all contribute to the occurrence and development of ILD [3]. The gene discussed is CCL2; the disease is pulmonary fibrosis.