NPPA and heart failure: Injection of a high (1 × 1010 vg g−1) or intermediate (5 × 109 vg g−1) dose of AAV-Cre into P1 SrfF/F mice triggered lethality and acute cardiomyopathy characterized by heart failure, ventricular dilatation, fibrosis, and the up-regulation of cardiac stress markers Nppa and Nppb (Fig. 1a–d).