hTid-1 has been seen to exhibit differential expression during developmental stages of cardiac tissue and pathological hypertrophy, and mice deficient in hTid-1/Dnaja3 have been found to have decreased mitochondrial DNA copy number and to develop dilated cardiomyopathy and progressive respiratory chain deficiency, subsequently causing the death of mice before 10 weeks of age. Here, DNAJA3 is linked to cardiac hypertrophy.