LIF and cancer: The differentially expressed factors produced exclusively in cultures with cancer cells included interleukin (IL)-1a, CXCL1, CXCL5/LIX, granulocyte colony-stimulating factor (G-CSF), IL-6, leukemia inhibitory factor, C-C chemokine ligand 2 (CCL2)/monocyte chemotactic protein-1, and CCL4/macrophage inflammatory protein (MIP)-1B, and the factors produced in cultures without cancer cells included IL-2, CSF-1/macrophage CSF, tumor necrosis factor-α (TNFα), vascular endothelial growth factor (VEGF), CXCL2/MIP2, and CXCL10 (Fig. 2g).