[Ethical reflections on cell reprogramming]

New advances in cell reprogramming, and particularly in obtaining iPS cells, have represented a promising possibility for avoiding the use of human embryonic cells in experimental research and clinical medicine, use which is ethically unacceptable, as obtaining these cells requires the destruction of human embryos. The road travelled to arrive at the discovery of iPS cells, and especially the ethical assessment of each of the steps taken to that end, are evaluated in this paper. The ethical judgement merited by the various uses that can be made of iPS cells is also examined, because just when it seemed that iPS cells could resolve the ethical problems inherent to the use of embryonic stem cells, new possibilities for using iPS cells, especially related with human reproduction, have opened up expectations for using these cells that are far removed from the most fundamental ethical standards. We conclude that the ethical debate on cell reprogramming and particularly on the experimental and clinical use of iPS cells remains open.