CX3CL1 and rheumatoid arthritis: Treatment with anti-CX3CL1 mAb (a neutralizing antibody) can prevent macrophage migration into the synovium of rheumatoid arthritis (RA) in a murine model, and humanized anti-CX3CL1 mAb has been used to treat patients with RA (Nanki et al., 2004; Tanaka et al., 2018).