An unstable plaque builds up inside the aorta of a mouse on a high-protein diet. A new study from Washington University School of Medicine in St. Louis reveals how high-protein diets increase atherosclerosis, especially unstable plaque that increases the risk of a heart attack. Immune cells called macrophages, which try to clean up the plaque, are shown in red. An important protein called mTOR is in green. Where mTOR is activated inside macrophages is shown in yellow areas. The teal area in the center indicates dying macrophages.