NPPB and cardiac hypertrophy: Intriguingly, transcripts for atrial natriuretic factor (ANF), and brain natriuretic peptide (BNP), canonical markers of cardiac hypertrophy and heart failure, were initially increased by 7 days, but dropped to control levels at 14 days (P < 0.05) in Mdm2f/f;mcm mice after Tam-administration, whereas alpha and beta myosin heavy chain (a/bMHC) mRNA were significantly downregulated by -39% and -47% (P < 0.001) (Fig 3K).