IL17A and rheumatoid arthritis: In 2005, Raza et al. reported that early RA of 3-month duration (mean: 9 weeks) or less is characterized by a distinct and transient synovial fluid cytokine profile of T cells, including IL-17, but not IFN-γ [48]; this study underlined the fact that the disease duration is very important in studies on the role of cytokines in the pathogenesis of diseases.