Phenotypic switching in AAA lesions from WT mice was accompanied by an increased expression of extracellular matrix degrading enzymes (MMP2 and MMP9) and their inhibitors (TIMP1 and TIMP2) (Figure 5A), along with higher serum gelatinolytic activities (Figure 5B) compared with Sham groups. This evidence concerns the gene MMP2 and triple-A syndrome.