CXCL12 and neoplasm: Cross-talk between cancer cells and non-malignant cells in the tumor microenvironment (TME) influences tumor growth, metastasis, and therapy resistance through multiple signaling pathways and feedback mechanisms such as growth factors (TGFβ, PDGF, FGF), contact molecules (Notch, Ephrins), and inflammatory molecules (IL1, IL6, CXCL12).1