ESRRG and heart failure: Also supporting the notion that reduced expression of genes related to oxidative metabolism in adult hERRγ-Tg mice is secondary to the progression of heart failure, the gene expression profile in younger transgenic mice is compatible with an expression profile resulting from increased ERRγ transcriptional activity, which includes increased mRNA levels of genes involved in mitochondrial oxidative phosphorylation, lipid metabolism, and postnatal contractile machinery.