Currently, five anti- TNFα biologic agents are widely used for RA treatment: infliximab (IFX), etanercept (ETN), adalimumab (ADA), certolizumab pegol, and golimumab (5–8).IFX is a chimeric human/mouse monoclonal antibody, in which the Fc domain is of human origin and the Fab’ domain is of mouse origin (4). The gene discussed is TNF; the disease is rheumatoid arthritis.