NG-monomethyl-L-arginine (L-NMMA), which is an arginine analogue that competitively inhibits the constitutive isoforms of NOS (cNOS: eNOS and nNOS) and iNOS, significantly reduced NO levels and concomitantly reduced synovial inflammation and tissue damage in streptococcal cell wall (SCW)-induced arthritis [6] and adjuvant arthritis [7] in rodents. This evidence concerns the gene NOS3 and Arthritis.