PROJECT NARRATIVE Advances in genome editing, embryology, and stem cell science are making it possible to imagine, and create, new kinds of human-animal chimeras that are both more biologically and more ethically complex than previously created chimeras. This project aims to develop clear, reasoned, and practical recommendations and educational materials to assist researchers, research institutions and their oversight bodies, funders and the public in identifying, understanding, and managing the ethical issues associated with human-animal chimera research.