CCL2 and breast cancer: Among the up-regulated genes, we found several genes that have been already shown to have a role in the pathogenesis of breast cancer and to be potentially involved in the interaction between MSCs and breast cancer cells, including VEGFA, IL6, EREG, HB-EGF, LIF, NGF, NRG1, CCL19, CCL2, CCL25 and CXCL3 (Table 1).