CXCR4 and neoplasm: CXCL12 plays a nuclear role in tumor-intrinsic EMT, invasion, survivability, and metastatic seeding mediated by tumor intrinsic CXCR4 signaling (through PI3K/AKT, MAPK/ERK, JAK/STAT) as well as CXCL12 chemotaxis induced by microenvironmental CXCL12 in stromal and endothelial cells.