CXCL12 and cancer: Although there were no similar results, the present findings may be explained as follows: As the cancer progresses, cancer-associated fibroblasts begin to continuously release growth factors such as TGF-β (transforming growth factor-β) and SDF-1/CXCL12 (stromal derived factor-1/C-X-C motif chemokine ligand 12), which chemically attract macrophages and promote M2 polarization [24] and, in parallel, modulate the extracellular matrix.