GCH1 and triple-A syndrome: In eNOS pre-uncoupled hyperphenylalaninemia (hph)-1 mice (deficient in GTPCHI), Gao et al. demonstrated that 14 days of Ang II infusion (0.7 mg/kg per day) resulted in 79% AAA incidence and 14% rupture, while none of the wild-type mice infused with Ang II died or developed AAA [96].