TNF and rheumatoid arthritis: In this field of research, RAW264.7 and RA-FLS cells are those commonly employed to investigate anti-inflammatory activities for RA, for the most part, based on the outcomes of TNF-α and IL-1β or IL-6 levels, and in some cases MMPs, while few studies reach further in the evaluation of transcription factors, using other mediators such as IL-1, IL-8 etcetera as well as Th1/Th2 ratio inter alia.