text: Brown and Goldstein discovered the LDL receptor and showed cholesterol is loaded into cells through receptor mediated endocytosis. Until recently cholesterol was thought of primarily as a structural component of the membrane. However, more recently, cholesterol uptake was shown to signal an immune response in macrophages. More importantly, the ability to efflux cholesterol through ABC transporters was shown to attenuate (i.e., shut down) the inflammatory response.