TNF and rheumatoid arthritis: During the progression of RA, TNF-α is an important physiological inflammatory mediator that exerts a variety of biological effects by acting on different receptors on target cells.5 TNF-α plays a key role in the pathogenesis of RA and maintenance of chronic synovial inflammation in joints.6 Therefore, in our study, we used TNF-α to stimulate MH7A FLSs to study proliferation and invasion in RA.