The naturally aged and the Tert-deficient mouse models share a relatively mild cardiac phenotype (mild eccentric remodeling, slight reduction in contractile function), Harlequin-deficient mice show spontaneous hypertrophic remodeling, while the Ercc1-deficient model displays a severe dilated cardiomyopathy at the age analyzed14,16,29. The gene discussed is TERT; the disease is dilated cardiomyopathy.