Intracellular lipid droplet formation, neutral lipid hydrolysis, and lipid catabolism are tightly regulated processes, which involve intracellular hydrolases, enzymes involved in lipid biosynthesis and regulatory proteins. Excessive lipid storage in lipid droplets is central to the pathogenesis of prevalent metabolic diseases, such as obesity, diabetes, and atherosclerosis. The research interests of our group focus on lipid and energy metabolism in non-adipose tissues and cells. Over the past years, we concentrated our efforts on the consequences of lipase deficiency on the regulation of lipid and energy metabolism in macrophages and the small intestine. We utilize transgenic and knockout mouse models with loss or overexpression of lipases or lipid-synthesizing enzymes to investigate the impact of the respective enzymes on whole-body lipid and energy metabolism and atherogenesis. In addition, we are interested in cell and tissue autonomous functions of the respective enzymes.