Atherosclerosis is the major cause of morbidity and mortality in America. This disease process is defined by the formation of vascular lesions that contain activated macrophages (MO) and dysfunctional endothelial (EC) and smooth muscle cells (SMC). The unfolded protein response (UPR) has been implicated as a cellular process that is induced in atherosclerotic lesions, and in cultured cells (MO, EC and SMC) treated with l