ACTA1 and triple-A syndrome: AAA lesions in γKO mice showed a marked and significant decrease of maximal aortic diameter and wall thickness (54% ± 4% and 60% ± 3% of decrease, respectively; P < 0.0001) (Figure 2B, C), lesser degrees of elastin degradation (VVG staining) and improved preservation of medial VSMC content (α‐SMA immunofluorescence) (Figure 2D, E).