A. Control and transgenic (TG) mice were subjected to sham or TAC surgery. Hematoxylin and Eosin (H&E) staining showed more enlargement of the transgenic heart compared to control. Masson’s Trichrome staining suggested an increase in fibrosis of the TG heart. Scale bar, 2 mm. B. Cardiac sections were used for wheat germ agglutinin (WGA) staining to visualize individual cells in the heart. Scale bar, 50 μm. C. GRP78 overexpression led to significant increases in cardiac cell size after TAC. N = 120–133. D. Overexpression of GRP78 in cardiomyocytes caused elevation in the ratio of heart weight to body weight, indicating more profound cardiac hypertrophic growth. N = 5–9. E. Quantification of heart weight/tibia length showed a trend of increase in the transgenic hearts compared to controls. N = 5–9. *, p < 0.05; ***, p < 0.001.