DNMT3A and cardiac hypertrophy: In the current study, we therefore focused on enzymes that contribute to increased CpG methylation such as the de novo methyltransferases Dnmt3a and Dnmt3b. For the first time, we examined the effects of combined cardiomyocyte-specific deletion of Dnmt3a and Dnmt3b in the setting of experimental heart hypertrophy and failure.