To more fully examine the impact of TNF-α signaling, ER stress activation, and VSMC dysfunction during AAA development, murine aortic VSMCs were isolated and stimulated with TNF-α which resulted in significant upregulation and activation of phosphorylated eIF2a, Atf4, and Chop at both the RNA and protein level (Figure 2, A–C). This evidence concerns the gene TNF and triple-A syndrome.