CXCL12 and cancer: They directly contribute to cancer cell proliferation, tumor growth, and invasion through stimulation of various growth factors and chemokines such as transforming growth factor β (TGFβ), vascular endothelial growth factor (VEGF), leukemia inhibitory factor (LIF), and C-X-C motif chemokine 12 (CXCL12) in context-dependent manner8–10.