RHOA and familial dilated cardiomyopathy: Our study showed that MALAT1 activated RhoA/ROCK pathway via sponging miR‐185‐5p and mediated HG‐induced oxidative stress, mitochondrial damage and apoptosis in cardiomyocytes, which indicate that MALAT1 is a vital regulator of DCM and acts as a promising target of diagnosis and therapy for DCM.