An individual’s cholesterol levels – both LDL (or “bad” cholesterol) and HDL (or “good” cholesterol) – are known to be a significant predictor of the risk for heart disease. While much attention has been focused on lowering levels of LDL, much less is known about the factors that determine HDL levels and how to alter these levels. However, research suggests that every 1 per cent increase in HDL levels results in an approximately 2-3 per cent decrease in risk for cardiovascular disease. With insight into how to raise HDL levels, a majority of the population might avoid developing heart disease. The gene ABCA1 has been identified as crucial to the production of HDL cholesterol, and is expressed in many tissues in the body. However, it is unclear which specific cell types or organs are responsible for the generation of HDL particles. Liam Brunham is investigating the specific role of ABCA1 in different tissues of the body and determining how ABCA1 in these tissues responds to different genetic and dietary environments. This research will increase the understanding of how ABCA1 functions to determine HDL levels, and suggest new ways to protect against heart disease.