The immunohistochemistry results showed that there was no positive expression of VCAM1 or MMP-9 in the control group, but VCAM1 expression was found in vascular endothelial cells and subendothelial foam cells in both the CHD and SCD groups, while MMP-9 was mainly expressed in the cytoplasm of inflammatory cells in the shoulder area and bottom of the lesion, as indicated by yellow or brown staining of some nuclei (Fig. 4C). This evidence concerns the gene MMP9 and coronary artery disorder.