The pSTAT3 in turn promotes the expression of IL-6, thus forming amplification loops of the production of IL-6, which can induce the vast expression of autocrine and paracrine cytokines and growth factors, including IL-8, CCL5, CCL2, CCL3, IL1-β, GM-CSF, VEGF, and MCP-1, which are highly expressed and play an important role in the generation and development of cancer. Here, CCL2 is linked to cancer.