Obesity is a risk factor in many of the major chronic diseases such as diabetes mellitus, and cancer. The ability to regulate the number of fat cells and/or the size of fat cells is a key in the development and physiology of obesity and also in the origin of chronic disease. Mammals have both brown adipose tissue (BAT), which utilizes lipids to generate heat in a process known as thermogenesis, and white adipose tissue (WAT) which stores excess energy as triglycerides in lipid droplets. Adipocytes are derived from multipotent mesenchymal precursor cells commit to preadipocytes and then either remain dormant or proceed to become differentiated adipocytes.

3T3-L1 cells are a well-characterized cell line to study the differentiation of adipocytes, and other mechanisms such as insulin-induced glucose uptake and mechanisms of obesity development. This model system has greatly advanced the understanding of the molecular basis and signaling pathways of adipogenesis. During terminal differentiation, the fibroblast-like preadipocytes undergo a series of morphological and biochemical changes to eventually accumulate lipid droplets. This in vitro differentitated adipocytes share similar morphology with adipocytes in vivo.