Cytokine production by fresh NKT cells. Summary plots show frequencies of IL-4 (left panels) and IFN-γ (right panels) producers among CD4 NKT cells (upper panels) and DN NKT cells (middle panels) in control, at-risk, and IDDM individuals. Representative FACS staining of IL-4 and IFN-γ are shown in control and IDDM individuals (bottom panels).