Four weeks after AngII infusion, the ATF4-knockdown (AngII+sh-ATF4) mice showed significantly smaller aneurysm formation compared with ApoE-/- (AngII) mice, while ATF4-overexpression (AngII+oe-ATF4) mice showed aggravated AAA formation (Fig. 2C). This evidence concerns the gene APOE and aneurysm.