CD4 and Behcet disease: After 7-day co-culture using monocytes (4 × 105/ml) and allogeneic responder CD4+ T cells (4 × 105/ml) from healthy controls, the proportion of IL-17+ and IL-17+/IFN-γ+ producing T cells was increased in BD monocyte-responder T cell cultures compared with that in control monocyte-responder T cell co-cultures (Fig. 5a and b).