MMP2 and triple-A syndrome: The protective effects and underlying mechanisms of EPA in AAA have been identified (Figure 4): (1) increased anti-inflammatory property of macrophages due to lessened inflammatory factor such as MMP2 and MMP9 levels122-124 (2) attenuated of mesenchymal stem cell (MSC) dysfunctions125 (3) suppressed the weakening of the vascular wall by inhibiting the elastin fiber degradation caused by nicotine126 (4) inhibition of endothelial cell-mediated inflammatory factors107.