The results show that naïve CD4+ T cells from patients with active BD cultured under Th17 polarizing conditions produced more IL-17 (7,351.2 ± 1,110.6 pg/ml) than did naïve CD4+ T cells from patients with inactive BD (4,875.1 ± 1,729.6 pg/ml; P = 0.033) and healthy controls (3,597.0 ± 1,089.2 pg/ml; P = 0.0003). The gene discussed is IL17A; the disease is Behcet disease.