PDE5A and cardiac hypertrophy: On the contrary, by using mice lacking the beta isoform of the cGMP-kinase type I (cGKI/PKGI) in cardiomyocytes, it was described that this kinase is not involved in the development of heart hypertrophy after TAC, suggesting that the modulation of cardiac hypertrophy can occur not exclusively through the Pde5a-cGMP-PKG pathway (29).