[What's your name? To build and label in vitro embryo models]

Emerging laboratory entities raise numerous ethical issues, one of which is their correct labelling. This article reviews the debate over naming stem cell cultures that reproduce in vitro the major developmental processes of the human embryo. Numerous labels have been proposed to refer to these entities, including embryo models, synthetic or artificial embryos, and embryoids, among others. We argue that each of these names goes with assumptions about the nature and potential of the entities they intend to designate. By listing the main terms used in the literature and presenting their advantages and disadvantages, we hope to unfold these assumptions and the ethical issues they entail.