Inadvertently, extracellular matrix proteinases (MMP-2, MMP-9 [58], cathepsins B, D, L, and S [59]) responsible for ECM cleavage, and proteinases inhibitors (a1-antithrypsin [19], cystatin-B [37], cystatin-C [60]) play a significant role in the aortic wall remodeling occurring in AAA pathogenesis with several studies revealing either positive or inverse correlations with AAA growth rates. The gene discussed is CTSB; the disease is triple-A syndrome.