NOS3 and cardiac hypertrophy: On the other hand, endothelial cells contribute to the microvessels and cardiac endothelial cells communicated with adjacent cardiomyocytes and fibroblasts by the secretion of bioactive molecule, such as nitric oxide (NO) synthesized by endothelial NOS (eNOS),4 and thus play an important role in the process of pathological cardiac remodelling, including cardiac hypertrophy and fibrosis.3, 5