Invasive BC cells (MDA-MB-231 cells) activate NF-κB signaling in MSCs by secreting IL-1β, inducing and increasing the production of the same chemokines (CXCL1, 3, 5, 6, 8, and CCL2, 5, etc.)as metastatic ER- BC [101]. This evidence concerns the gene CCL2 and breast cancer.