CCL17 and liver cancer: In liver cancer, chemokines such as C-C Motif Chemokine Ligand 17 (CCL17), C-C Motif Chemokine Ligand 22 (CCL22), C-C Motif Chemokine Ligand 28 (CCL28), and C-X-C Motif Chemokine Ligand 9 (CXCL9) are produced, which bind to these receptors, and consequently recruit a substantial number of Tregs to the liver cancer site (3).