In sharp contrast, systemic treatment of mice with the EP4 antagonist, ONO-AE3-208, or a heterozygous EP4+/− genotype decreased vascular inflammation and protected from angiotensin II-induced abdominal aortic aneurysm formation on an ApoE-deficient background (Cao et al., 2012; Yokoyama et al., 2012). The gene discussed is PTGER4; the disease is abdominal aortic aneurysm.