TLR4 and acute coronary syndrome: Other studies showing increased TLR4 expression in macrophages in symptomatic carotid atherosclerotic plaques [63] and increased TLR4 expression in circulating monocytes of patients with coronary atherosclerosis [64] and patients with acute coronary syndrome compared to stable angina [65], [66], also suggest that TLR4 is involved in vascular inflammation in humans.