CSC-derived cardiomyocytes were identified by GFP and α-actinin double-positive staining was located in the infarct sites of CSC-engrafted MI hearts as shown in Fig. 3a, b, but newly formed myocytes were reduced in MI hearts that received Oct3/4 siRNA-treated CSCs. This evidence concerns the gene POU5F1 and myocardial infarction.