Effect of prednisone on the IFN-score validated in cohort II. In peripheral blood of 182 RA patients, gene expression levels of 8 interferon response genes were averaged to calculate the IFN-score. The IFN-score was evaluated in relation to prednisone use and prednisone dose. A) Comparison of IFN-score between prednisone-untreated (PREDN−) and prednisone-treated (PREDN+) RA patients; B) The relation between prednisone dose and IFN-score, assessed using Kruskal-Wallis. RA, rheumatoid arthritis.