Circ-0008433 regulates the expression of matrix metallopeptidase 2 (MMP2) by competitively binding to miR-181c-5p and miR-181b-5p, which further recruits NK cells to attack arterial elastic fibers, remodel blood vessels, and promote the progression of aneurysms 45 (Figure 2C). This evidence concerns the gene MMP2 and aneurysm.