In triple-negative breast cancer, CAFs were described to secrete C-X-C motif chemokine ligand 12 (CXCL12) and insulin-like growth factor-1 (IGF1) factors that promote the expansion of high metastatic clones with high Src activity, a known predictor of bone metastasis (77). The gene discussed is CXCL12; the disease is triple-negative breast carcinoma.