Further analysis revealed that the expression level of MMP-2 was significantly higher than TIMP-1 in the control group (Figure 3), while the expression level of TIMP-1 in the TAO group (about 5 times that of the control group) was significantly higher than the increase in MMP-2 (about 0.7 times that of the control group). This evidence concerns the gene MMP2 and thromboangiitis obliterans.