Oct3/4(+) CSC transplantation resulted in a decrease of interstitial collagen in response to MI, which was abolished in hearts receiving Oct3/4 siRNA-treated CSCs, as the collagen content remained significantly elevated in those groups (Fig. 6d), indicating that the prevention of post-MI apoptosis and fibrosis by CSC transplantation is dependent on the participation of Oct3/4. Here, POU5F1 is linked to myocardial infarction.