CXCL1 and lung cancer: Lung cancer CAFs exert their immunosuppressive effects by secreting chemokines, including CCL2, chemokine (C-C motif) ligand 7 (CCL7), chemokine (C-X-C motif) ligand 1, 5, and 8 (CXCL1, CXCL5, CXCL8), and IL-6, which promote the differentiation of CD14+ monocytes into immunosuppressive MDSCs.