In addition, adult murine hearts exhibit cardiac hypertrophy with genetic inactivation of MSTN (Biesemann et al., 2014), and Jackson et al. (2012) reported that MSTN−/− mice have heavier hearts than the myocardium of WT mice over a wide age range (3–24 months) (Jackson et al., 2012). Here, MSTN is linked to cardiac hypertrophy.