Recently, it has been reported that TLR5 signaling is associated with pathogenesis of inflammatory bowel disease,(15) rheumatoid arthritis,(16) cardiac fibrosis,(17) and cystic fibrosis lung disease.(18) These reports suggested that over-activation or increased expression of TLR5 exacerbates the inflammatory response; thus TLR5 may be a therapeutic target for these diseases. The gene discussed is TLR5; the disease is rheumatoid arthritis.