CD68 and atherosclerosis: Macrophage foam cells are a hallmark of atherosclerosis and key integrators of inflammatory and metabolic signals in atherosclerotic plaques.2 More recently, vascular smooth muscle cells (VSMCs) within the arterial wall were also found to contribute significantly to foam cell populations.12,16–19 Studies have shown that VSMC-derived foam cells comprise 30% to 70% of foam cells in mouse and human atherosclerotic plaques12,16–19 and express macrophage markers such as Mac-2 (galectin-3) and CD68 when cholesterol loaded.