Hph-1 mice treated with Ang II at 0.7 mg/kg per day, show an increased eNOS uncoupling and AAA formation.5 However, the hph-1 mouse has a global BH4 deficiency, affecting all cells and tissues, so is not possible to dissect out how BH4 deficiency mediates the increase in vascular pathology. The gene discussed is AGT; the disease is triple-A syndrome.