CCL2 secreted by tumor cells promotes cancer cell extravasation through a dual mechanism (Figure 8) (1): CCL2 attracts CCR2+ Ly6C high expressing monocytes, which are used by tumor cells as carriers across the vessel wall (2); CCL2 enhances the permeability of local blood vessels through endothelial cells (210). The gene discussed is CCL2; the disease is neoplasm.