Here, serum concentrations of Fractalkine and TNFa were highly correlated in all groups (pSS: r = 0.689 and p<0.0001; RA: r = 0.608 and p = 0.0005; SLE: r = 0.563 and p = 0.003; data not shown), suggesting a strong pathophysiological relationship between these two biomarkers. The gene discussed is TNF; the disease is rheumatoid arthritis.