Atherosclerosis is a multifactorial chronic vascular inflammatory disease characterized by lipid deposition and even lipid plaque formation in the vascular intima.Macrophage cholesterol accumulation and foam cell formation are the hallmarks of early atherogenesis.However,the underlying mechanisms of foam cell formation are not fully elucidated.Herein,we hypothesize that the signaling model composed of the oxidized low density lipoprotein(ox-LDL),the lectin-like oxidized low density lipoprotein receptor-1(LOX-1)and the reactive oxygen species(ROS) plays an important role in foam cell formation.In this model,ox-LDL is the activating factor;LOX-1,the main ox-LDL receptor expressed in endothelial cells,acts as a signal transducer while the ROS,a direct product of ox-LDL binding with LOX-1,is regarded as a catalyst and an inducer.