However, when we examined the mRNA levels and supernatant content of inflammatory cytokines in hUC-MSCs and IL-6-hUC-MSCs, we found that the levels of several cancer-promoting cytokines, including CCL5, PDGF-BB, MCP-1 and TNFα, were markedly downregulated in the IL-6-hUC-MSCs. This evidence concerns the gene CCL5 and cancer.