As one would expect, plaques obtained from patients with diabetes were characterized with a higher content of macrophages and a higher expression of nitrotyrosine (a marker of oxidative stress), TNFα and MMP-9 (metalloproteinase 9, the key enzyme that destabilizes atherosclerotic plaques by means of extracellular matrix protein degradation) in comparison to non-diabetic patients. Here, TNF is linked to diabetes mellitus.