Forced expression of PPARGC1A has been demonstrated to activate mitochondrial biogenesis and metabolism in cardiac myocytes in vitro, and cardiac-specific over-expression of PPARGC1A in transgenic mice has led to mitochondrial proliferation and loss of sarcomeric structure in cardiac myocytes, leading to a dilated cardiomyopathy [20]. The gene discussed is PPARGC1A; the disease is dilated cardiomyopathy.