HIPK1 and persistent truncus arteriosus: We further isolated adult mouse cardiomyocytes and noncardiomyocytes (majorly fibroblasts) from sham and TAC mice, and found that HIPK1 was significantly upregulated in cardiomyocytes from the TAC group, indicating a prominent function of HIPK1 in cardiomyocytes (Figure S1c, Supporting Information).