摘要From May 2002 to July 2002, I have the opportunity of visiting the laboratory led by Dr. Shih Chu-Cheh at the City of Hope National Medical Center in California, USA to learn some basics of stem cells. Since the main focus was the investigation of the potential of human neurostem cells, I was working on concentration of pseudotyped virus and their production; the ability of human neurostem cells developed into pancreas-like cells and in vivo model of human pancreas/liver transplantation. Through these work, I felt that in vivo model might be a quick way before large scale of clinical trials to estimate the risk and benefit of potent stem cells. Identify certain genes and molecular levels in the potent stem cells might be critical to the gene shift responsible for the trnasdifferentiation. Gene transfer might also be helpful in stem cell research in tracing its frequency. Finally, cooperation is also important among each team and is probably the only key element to successful research in a limited period of time.