IL17A and Behcet disease: In active BD patients with a response to S-Ag, the trend showed that IFN-γ was positively correlated with TNF-α and negatively correlated with IL-17 while in active BD patients without a response to S-Ag, the postive correlative trends were observed between IFN-γ and TNF-α or between IFN-γ and TNF-α.