CCL17 and neoplasm: TAMs are also able to express immune checkpoint modulators such as PD-L1 and various chemokines (C-C motif chemokine ligand 17 (CCL17), CCL22, C-X-C motif chemokine ligand 10 (CXCL10)) which attract effector/activated T regs that exert an immunosuppressive action and promote tumor growth (Figure 1C) [36,37,38,41,42,43].