Masson staining results showed that collagen deposition in myocardium was significantly increased in the tissues of TAC+NC-RNAi mouse heart compared with sham group, but was decreased in TAC+SerpinE2-RNAi group compared with TAC+NC-RNAi group; meanwhile, the results collected from transmission electron microscopy showed that, in TAC+NC-RNAi group, the shape of the myofilament was ambiguous and mitochondria were disordered while, these effects were ameliorated by knockdown of serpinE2 (Figure 6A-B). The gene discussed is SERPINE2; the disease is persistent truncus arteriosus.