F-1394 is an acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor. F-1394 both prevents the formation of atherosclerosis and accelerates its regression without affecting the serum TC level, indicating that F-1394 acts directly on the arterial wall. F-1394 significantly reduced neointimal thickening and the extent of macrophages in lesions without affecting serum cholesterol levels. In vitro, F-1394 attenuated foam cell formation in mouse peritoneal macrophages.