TGFB1 and persistent truncus arteriosus: Immunohistochemistry analysis with ascending aorta tissues also showed that down-regulation of α-SMA (Figure 5H), but up-regulation of COL-1 (Figure 5I), TGF-β1 (Figure 5L), Angptl1 (Figure 5J) and PCNA (Figure 5K) in TAC model as compared to sham surgery treated mice.