This treatment was sufficient to bring the heart size (HW/TL) of MKK6 KO animals close to that of WT age-matched controls, which corresponded with a robust reduction in cardiomyocyte cross-sectional area in MKK6 KO mice (Figure 7E-G), altogether suggesting that the cardiac hypertrophy in MKK6 KO mice results from hyperactivation of mTOR signaling. Here, MTOR is linked to cardiac hypertrophy.