HMGB1 and persistent truncus arteriosus: Moreover, TAC‐induced cardiac hypertrophy was observed at 2 weeks after TAC, which was significantly enhanced by exogenous HMGB1 overexpression in myocardium, as indicated by interventricular septal wall (IVS) thickness and left ventricle posterior wall (LVPW) thickness at both systole and diastole (P < 0.05).