Results from GSE36700 containing synovial tissue samples from 5 OA, 4 SLE, 5 microcrystalline arthritis (MA) and 7 RA patients confirmed the differential expression of IRF4 (adjusted p = 8.4·10−4), again being upregulated in RA (Figure 5D). The gene discussed is IRF4; the disease is systemic lupus erythematosus.