During the past year, we have made significant progress in the proposed research. One most important finding is the discovery of the immunogenicity of the cells derived from induced pluripotent stem cells (iPSCs). This immunogenicity is due to the abnormal gene expression during the differentiation of iPSCs. This finding, published in the journal Nature, indicates that we need to perform more research on iPSCs before moving forward into clinical trial. Another major finding is the discovery of a safer way to improve the efficiency of iPSC production. In addition, we have made some progress in developing a genetic approach to eliminate the teratomas risk associated with the undifferentiated pluripotent stem cells.