Co-injection of breast cancer cells and fibroblasts also promotes the progression of ductal carcinoma in situ to invasive breast carcinoma by stimulating chemokine (C-X-C motif) ligand 14 (CXCL14) and chemokine (C-X-C motif) ligand 12 (CXCL12) production [14]. The gene discussed is CXCL12; the disease is invasive breast carcinoma.