A similar increase could be observed when RA synovial tissue was compared to samples from healthy subjects with the exception of CXCL1. Furthermore, expression of regulators of the complement system was promoted by mechanical stresses such as CFP, the only known positive regulator of the complement system, and C1QTNF6 which is an endogenous complement regulator, both in healthy C57BL/6 and TNF∆ARE mice. This evidence concerns the gene CFP and rheumatoid arthritis.