CCL2 and hepatocellular carcinoma: Besides, Jiang et al. showed that peri-tumor associated fibroblasts may also play a significant role in tumor progression by recruiting tumor stem cells, maintaining the characteristics of stem cells and enhancing intrahepatic HCC metastasis by secreting IL-6, CXCL1, CCL2, SCGF-β, CXCL8, HGF and some other cytokines [12].