For example, TGF-β1 is a critical mediator of renal fibrosis, and it can upregulate MCP-1 in rat renal tubular epithelial cells.[71] Further study of cross-talk between TGF-β1 and MCP-1/CCR2 may deepen the understanding of the pathogenesis of renal fibrosis. This evidence concerns the gene CCL2 and renal fibrosis.