Mechanistically, miR‐30c‐5p, miR‐126‐5p and miR‐126‐3p co‐suppress cardiac FOXO3 expression, and loss of them abrogates their repression on FOXO3 thus aggravating cardiac apoptosis and autophagy in DCM development. This evidence concerns the gene FOXO3 and familial dilated cardiomyopathy.