Generation and application of human iPS cells

Human embryonic stem (ES) cells are capable of unlimited proliferation and maintenance of pluripotency in vitro; these properties may lead to potential applications in regenerative medicine. However, immune rejection hampers the allogenic application of human ES cells. Over-expression of several specific transcription factors has been used to reprogram human adult cells into induced pluripotent stem (iPS) cells, which are similar to hESCs in many aspects. The iPS technique makes it possible to produce patient-specific pluripotent stem cells for transplantation therapy without immune rejection. However, some challenges remain, including viral vector integration into the genome, the existence of exogenous oncogenic factors, and low induction efficiency. Here, we review recent advances in human iPS methodology, as well as remaining challenges and its potential applications.