For instance, the cytokines TNF-α, IL-1α, IL-1β, and IL-6, and the chemokines CCL2 (MCP-1), CCL5 (RANTES), and CXCL2, have been shown to play pro-fibrotic roles in bleomycin-induced lung fibrosis in mice and in certain human fibrotic lung diseases, such as IPF and asbestosis. This evidence concerns the gene CCL2 and idiopathic pulmonary fibrosis.