Peripheral artery disease is a disease that contributes to significant morbidity and mortality of millions of Americans yearly. Very little is known about the pathophysiology of atherosclerosis in peripheral artery disease. We plan to collect peripheral arteries from patients undergoing amputation for end stage peripheral arterial occlusive disease. By extracting the RNA from these arteries and comparing them with RNA expression from normal arteries, we hope to have a better understanding of the pathophysiology of atherosclerosis in this setting. We aim to prove the hypothesis that a novel gene expression pattern can be discovered by the successful extraction of RNA from plaques from human peripheral arteries.