Patients with RA had significantly higher levels of TNF-α and IL-6 (median 172 pg/ml, IQR 117–308 pg/ml; and 917 pg/ml, IQR 455–2842 pg/ml, respectively) compared with HC (82 pg/ml, IQR 50–97 pg/ml; and 231 pg/ml, IQR 159-452 pg/ml, respectively; p < 0.001). Here, TNF is linked to rheumatoid arthritis.