Lipids are the most abundant metabolite in the plasma, accounting for more than 60 percent of the circulating metabolite pool. These plasma lipids function as stored fuel, structural elements, and signaling molecules that regulate cardiovascular disease and type 2 diabetes. Despite their established biological importance, the majority of observed plasma lipids are unidentified, and their function is unexplored. Judith Simcox and her lab work to identify novel lipids in the circulation, determine how their production is regulated, and discover how these plasma lipids function in metabolic disease.