Stimulation of human monocytes with CCL2 in a study by Matsushima et al. led to a growth inhibitory effect for the HT29 colon cancer cell line and the A375 C-5 melanoma cell lines assessed with a [3H]-thymidine incorporation assay in vitro, in which monocytes were grown adherently and tumor cells were added in suspension for coculturing and the incorporation of [3H]-thymidine was measured (37). Here, CCL2 is linked to malignant colon neoplasm.