Breakdown of the potentiality principle and its impact on global stem cell research

Totipotency, defined as the ability of a single cell to generate an entire individual, has traditionally served as a cornerstone to frame the moral relevance of nascent human life. This "potentiality principle" has served as an ethical reference point for shaping legal regulations for stem cell research in most Western countries. Based on heterogeneous ethical, religious, and political views, different countries cope with recent advances in mammalian cloning and reprogramming in a remarkably diverse manner. This and related issues were key topics at a recent meeting held in Berlin, Germany, on ethical aspects of stem cell research in Europe. An emerging view from this event is that international heterogeneity in stem cell politics and legislation must be overcome in order to develop this field toward biomedical application.