Because IL-18 promotes the adhesion of B16 melanoma cells to the hepatic microvascular endothelium via VCAM-1-dependent mechanism [13,15], we next studied the effect of RVL on the VCAM-1 expression level in primary cultured hepatic endothelial cells given either recombinant murine IL-18 or B16M-CM. Here, VCAM1 is linked to melanoma.