NPPB and cardiac hypertrophy: Consistent with previous reports, hearts of mice with DbCM exhibited increased features of myocardial hypertrophy and fibrosis, including enlarged myocyte area, elevated protein levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and myosin heavy chain 7 (β-MHC), and enhanced accumulation of collagen fibres (Fig. 1i–m and Extended Data Fig. 1e).