Another example is the tylophorine-based compounds DBQ 33B (2-Ethyl-7,10,11-trimethoxy-1,2,3,4-Tetrahydrodibenzo [f,h]-isoquinolin-4-ol), which can down-regulate expression of iNOS and significantly improve the severity and morbidity of RA [88]. This evidence concerns the gene NOS2 and rheumatoid arthritis.