MKI67 and persistent truncus arteriosus: For this, 5-bromo-2-deoxyuridine (BrdU), phospho-histone H3 (pH3), and Ki67 immunostaining was performed together with α-actinin or cardiac troponin I (cTnI) to identify cardiomyocyte proliferation in the hearts of mice in the sham, 30G, and 32G TAC groups.