Modification of the glycolipid ligands for natural killer T (NKT) cells might be an efficient approach to improve their stimulatory activity or to shift the proportional release of Th1 and Th2 cytokines. The chemical modified iGb3 analogue, 4‴-dh-iGb3, made by introducing a hydroxyl group at C4 of iGb3 and removing the 4″′ hydroxyl group of the terminal galactose, could increase the stability of the CD1d/antigen/TCR ternary complex and IFN-γ signaling ofNKTcells, and thus stimulate more IFN-γ production by NKT cells. 4‴-dh-iGb3-loaded dendritic cells significantly inhibit growth of subcutaneous melanoma and suppress lung metastasis in C57BL/6 mice. The 4‴-dh-iGb3-loaded dendritic cell vaccine may serve as a potent new NKT-based therapy against tumors. For details, see article by Zhou and colleagues on page 1375.