CD1D and neoplasm: In co-cultures with CD1d+ tumor cell lines, the CD1d-Vδ2 bsTCE triggered type 1 NKT cells to secrete Th1 and Th2-type cytokines, including IL-2, IL-4, tumor necrosis factor (TNF), and interferon (IFN)-γ, whereas Vγ9Vδ2-T cells mainly secreted TNF and IFN-γ (Figure 2A).