For example, peri-tumor tissue-sourced fibroblasts secrete various cytokines, including IL-6, CXCL1, CCL2, SCGF-β, CXCL8 and HGF, to recruit cancer stem cells, maintain cancer stemness and promote intrahepatic metastasis of HCC [8]. The gene discussed is IL6; the disease is hepatocellular carcinoma.