CCL2 and neoplasm: After two weeks of exogenous CCL2 delivery, we observed that the net tumor contribution to the weight of the lung in the CCL2 treated group was significantly increased [314 ± 83 mg, n = 5] in comparison with the PBS control group [184 ± 45 mg, n = 7] (Wilcoxon rank sum test, p = 0.006) (Fig. 6a and b, comparing 6Bb to Ba).