The serum levels of TNF-α were elevated in BD subjects regardless of whether they were positive or negative for HERV-W ENV protein (Fig. 2C), as supported by ANOVA (F(4,71) = 4.50; p < 0.01) and subsequent post-hoc comparisons revealed significant differences between HC subjects and BD/CL1 (p < 0.05) or BD/CL2 (p < 0.05) subjects. Here, TNF is linked to Behcet disease.