CCL2 and cancer: Furthermore, genes enriched in the gene set “proinflammatory and profibrotic mediators” (Fig. 2D) consist of the upregulation of molecules previously implicated in OS lung metastasis, such as IL-6, CCL2, and CXCL8 (34), or reported to be upregulated in metastasis-associated fibroblasts (MAF) in other cancers (35).