MT-ND4 and familial dilated cardiomyopathy: Hence, we detected the levels of mtDNA (Dloop1, Dloop2, Dloop3, CytB, 16S, and ND4) in the cytosol and found that all of these mtDNAs were upregulated in the cytosol of DCM mice compared with the control group (Fig. 1c), indicating the escape of mtDNA into the cytosol.