TPT1 and Ventricular arrhythmia: The present study revealed the following: TCTP is predominantly expressed in the intercalated discs of mouse heart tissue; TCTP is located close to Cx43 in cardiomyocytes; TCTP silencing reduced the formation of Cx43 gap junction channels at the intercellular contacts between cardiomyocytes; TCTP silencing significantly attenuates GJIC in cardiomyocytes; and in cardiomyocytes-specific TCTP overexpressing mouse, the development of catecholamine-induced ventricular arrhythmia was attenuated.