Ruiz-Lozano reported that APJ is a bifunctional receptor for both mechanical stretch and the endogenous peptide apelin and play a different role in cardiomyocyte hypertrophy. The paper “APJ acts as a dual receptor in cardiac hypertrophy” is reported in the nature journal (nature,488:394-398, 16 July 2012) . It is reported that APJ is a bifunctional receptor for both mechanical stretch and the endogenous peptide apelin in cardiomyocyte hypertrophy. Activation of APJ by stretch is a G-protein-independent way to induce hypertrophy; while apelin stimulates APJ to activate Gai and elicits a protective response. By sensing the balance between these stimulates, APJ occupies a pivotal point linking sustained overload to cardiomyocyte hypertrophy. This is a significant breakthrough for apelin/APJ system and it provided a new direction of APJ regulation, and it also provides a new treatment of myocardial hypertrophy.