Subsequent coculturing of these macrophages with CT26 cells showed that macrophage cytotoxicity (assessed by [3H]-thymidine release from lysed cells) toward CT26 tumor cells was increased in a CCL2-dependent manner, as the addition of CCL2 strongly increased cytotoxicity and the addition of anti-CCL2 antibody reduced cytotoxicity. This evidence concerns the gene CCL2 and neoplasm.