Furthermore, the expression of synovial fibroblast CX3CL1 and CX3CR1 expressed by CD8+ T cells has been shown to positively correlate with RA severity (125) and monoclonal antibody treatment targeting CX3CL1 has shown to be successful in early phase clinical trials in RA (126). This evidence concerns the gene CX3CL1 and rheumatoid arthritis.