CX3CL1 and rheumatoid arthritis: In contrast, FKN reportedly contributes to the pathological process of vascular and tissue injury in inflammation-mediated diseases and pathological conditions, including atherosclerosis, glomerulonephritis, rheumatoid arthritis, and transplant rejection, by enhancing migration and adhesion of CX3CR1-expressing leukocytes and promoting their transmigration to inflammatory sites (24, 27, 28).