IFNG and Behcet disease: Additionally, T helper type 1 (Th1)/Th17 cytokine polarization of CD4+ T cells is a consistent finding in disease lesions and in peripheral blood where increased interferon (IFN)‐γ, tumour necrosis factor (TNF)‐α, interleukin (IL)‐8 and IL‐17 levels have been correlated with BD activity 10.