CXCL16 is regulated by two groups of cytokines: Th2-related cytokines IL-4 and IL-10, which inhibit the secretion of CXCL16 in monocytes/macrophages from RA patients; and Th1-related cytokine IFN, which enhances CXCL16 secretion (23). Here, CXCL16 is linked to rheumatoid arthritis.