CASP3 and myocardial infarction: In addition, exercise preconditioning alleviated cardiac hypertrophy, decreased cardiac fibrosis, increased cardiac capillary density, and decreased cardiac apoptosis and caspase 3 cleavage in control mice with MI, while these protective effects exerted by exercise preconditioning were abolished in cardiac-specific PP2Cm KO mice (Figure 5F–I).