A Simple and Efficient Method for In Vivo Cardiac-specific Gene Manipulation by Intramyocardial Injection in Mice Yanan Fu*1,2, Wenlong Jiang*2, Yichao Zhao*2, Yuli Huang1, Heng Zhang1, Hongju Wang1, Jun Pu1,2 1Department of Cardiology, The First Affiliated Hospital of Bengbu Medical College, 2Department of Cardiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University Here we present a protocol for cardiac-specific gene manipulation in mice. Under anesthesia, the mouse hearts were externalized through the fourth intercostal space. Subsequently, adenoviruses encoding specific genes were injected with a syringe into the myocardium, followed by protein expression measurement via in vivo imaging and Western blot analysis.