To validate our microarray findings at different phase of AA, we performed qPCR on a set of randomly selected genes among those relevant to arthritis: IFN-γ, IL-10, IL-17, Nos2, CCR5, Socs1 and Socs3. The Bland-Altman plots (Figure 2D) suggest that all expression levels are within the 95% confidence limits for agreement, suggesting reasonable agreement of the expression obtained with the two methods. This evidence concerns the gene IL17A and arthritic joint disease.