These circulating mediators all have pleiotropic effects, but specific intrahepatic and tumor-promoting functions have been ascribed to them: circulating CCL15 has been associated with presence of suppressive monocytes in the liver; MMP-3 is linked to HGF-induced HCC invasion [5,8], while the growth factors M-CSF, SCF, SCFG-β and HGF are all known to contribute to tumor progression in a broad spectrum of tumors [9]. The gene discussed is KITLG; the disease is hepatocellular carcinoma.