IL6 and breast cancer: Amongst these secreted factors, IL-6, apro-inflammatory cytokine, has been proven to contribute to the metastatic cancers,including HCC [6], gastric cancer [7], breast cancer [8], and lung cancer [9].Previous studies showed that BMSC produces a significant amount of IL-6, as well asIL-8, prostaglandin E2 (PGE2), and VEGF [10].Considering the complexity of the multifunctional composition of BMSC-CM, it shouldbe further addressed whether BMSC-CM regulates HCC through an IL-6-dependentpathway.