In DCM rat hearts, TUNEL staining showed an increase in apoptotic cells in DCM hearts, decreased expression of anti-apoptotic protein Bcl-2, and significantly increased ERS-related proteins GRP78, caspase-9, and caspase-12; In addition, in vitro experiments significantly increased the expression of GRP78, IRE-1α, and CHOP in H9c2 cells cultured in HG; all suggesting that ERS may contribute to DCM development through the apoptotic pathway in DCM (Park et al., 2021). Here, ERN1 is linked to familial dilated cardiomyopathy.