Transplantation of derivatives of ES cells

Solid organ transplantation and hematopoietic stem cell transplantation always face major obstacles in the scarcity of organs and hematopoietic cells from human donors. Theoretically the establishment of human ES cell lines and multilineage differentiation from human ES cell lines could make transplantation therapy without donors practical. The clinical promise of human ES cell-based therapies is enormous. However, appropriate derivation of human ES cells to functionally matured and differentiated cells has not been established and serious concerns including ethical problems, safety, efficacy and strategy for preventing rejection will need to be addressed before clinical trials can be initiated.