We found that BRG1 was downregulated in the cardiac tissues of DCM mice and in cardiomyocytes cultured with high glucose and palmitic acid (HG/PA), which was accompanied by accumulation of dsDNA and activation of the cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) signaling pathway. This evidence concerns the gene CGAS and familial dilated cardiomyopathy.