The universe of antigens recognized by the immune system has recently been expanded to include not only protein antigens but also lipid and lipopeptide antigens. By orchestrating immunological, cell biological, biochemical and structural approaches, our laboratory aims to establish the molecular and cellular basis underlying “lipid immunity” and disclose its relevance to cancer, microbial infections, and autoimmunity. These studies have important medical implications, including development of a new type of lipid-based vaccines.