In accordance, we further demonstrated that COMP inhibited the phosphorylation of ERK1/2 induced by 15-min stimulation with AngII (Supplementary information, Fig. S13e), which was attributable to β-arrestin-2-related signaling.59 Thus, we mainly focused on the effect of COMP on β-arrestin-2-related AT1 signaling in the pathological process of AAA. This evidence concerns the gene COMP and triple-A syndrome.