TNNT2 and cardiac hypertrophy: To validate the role of Lgr6 in cardiac hypertrophy, we generated adeno‐associated virus 9 (AAV9) carrying the cTnT promoter to selectively knockdown Lgr6 expression in mouse cardiomyocytes (AAV9‐cTnT‐shLgr6 and AAV9‐cTnT‐null) (Figure S3A, Supporting Information).