In recent years, dramatic experiments have revealed the ability of multiple types of stem cells grown under controlled conditions to self-organize into structures that resemble native tissues. Self-organizing two- and three-dimensional cultures which reflect events in the early embryo, here called “embryoids”, can be perturbed and observed to a degree impossible for mammalian embryos developing in utero, and have opened the door to making progress on previously intractable questions. Furthermore, human embryoids represent one of the only experimental windows we have into the early stages of our own development.

A key current challenge is to go beyond proof of principle demonstrations that these models are possible and use them to explore important questions in developmental biology. This meeting will bring together researchers with backgrounds in biology, physics, and engineering, working on a variety of embryoid systems, as well as actually embryos, to address the following aims:

1. How well do embryoids reflect actual development and what are gold standards for determining this, particularly for human where access to embryos is limited?
2. How can we use embryoids to answer questions that cannot be addressed with embryos alone: what knowledge has been gained so far and what are key questions which can be answered?
3. What ethical questions are posed by human embryoids and how can consensus be achieved?

While there are meetings on human development and on organoids, no current meetings focus directly on the field of embryoids and the unique challenges and opportunities posed by this field.