Human CCL18 is encoded by the CCL18 gene located on the chromosome 17. As also named MIP-4, it shares 61 % sequence identity to human MIP-1α. CCL18 is mainly expressed by lung and some lymphoid tissues like lymph nodes express CCL18 at low level. It is chemotactic for both activated (CD3+) T cells and nonactivated (CD14-) lymphocytes, but not for monocytes or granulocytes. Involved in B-cell migration into B-cell follicles in lymph nodes. CCL18 plays a role in both humoral and cell-mediated immunity responses.