CXCL12 and neoplasm: In the tumor stroma, CAFs play an important role by directly interacting with tumor cells and by the secretion of extracellular matrix proteins (i.e. collagen), matrix metalloproteinases (MMPs), proteoglycans (i.e. laminin), chemokines (i.e. CXCL12/SDF1), vascularisation promoting proteins (i.e. VEGF) and other factors which affect tumor cells proliferation, invasiveness, survival and stemness (i.e. TGF-β) [5, 10–15].