These findings give a plausible explanation for the tumor-promoting biological effects of seroma fluid, as it is highly enriched with many factors such as IL-6, IL-8 and MCP-1/CCL2 that have been shown to possess strong pro-proliferative and pro-oncogenic biological activities (Balkwill and Mantovani 2001). This evidence concerns the gene CXCL8 and neoplasm.