We then assessed vascular inflammation, matrix metalloproteinase (MMP)-induced extracellular matrix degradation and oxidative stress in the suprarenal aortas, since these features are the major pathologies of AAA.19,33 Compared to WT mice, COMP–/– mice exhibited greater inflammatory cell (CD45+ leukocytes, Mac-3+ macrophages, and CD4+ T cells) infiltration and increased MMP activity upon AngII infusion for 28 days (Supplementary information, Fig. S2a, b). This evidence concerns the gene CD4 and triple-A syndrome.