Fatty streakstext annotation indicator are the first signs of atherosclerosis that are visible without magnification. A fatty streak consists of lipid-containing foam cells in the arterial wall just beneath the endothelium. It appears as a yellow discoloration in the artery's inner surface and occurs in the aorta and coronary arteries of most people by age 20. Over time, these fatty streaks can evolve into atherosclerotic plaques or they can remain stable or even regress. The image below on the left is a photograph of the inside of an artery; one can see a fatty streak beneath the thin endothelial lining of the artery. The cartoon on the right summarizes the steps by which the fatty streak evolves.