CXCL5 and rheumatoid arthritis: Indeed, the serum levels of CXCL5 correlate with autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, glomerulonephritis, pemphigus vulgaris, and bullous pemphigoid with several inflammation factors [16–18, 35], though the main sources of CXCL5 is not fully investigated in each reports.