To test this, PBMCs from 30 CMV‐seropositive controls and 29 CMV‐seropositive RA patients were stimulated with Staphylococcal Enterotoxin B (SEB) for 6 h and analyzed for production of cytokines, IFN‐γ and TNF‐α (Table S2 and 3; Figure 6A). Here, TNF is linked to rheumatoid arthritis.