KDR and triple-A syndrome: We found that sGPNMB significantly increased the expression of CD44, rather than KDR, in HASMCs (Figure 4E), consistent with the scRNA-seq data in Figure 4A. VSMCs are the predominant cell type within the aortic wall and its dysfunction, including apoptosis, phenotypic switching, and enhanced elastolysis, contributes to AAA development and progression (1–3, 29, 30).