Chimeras are organisms composed of cells from two or more different species. This field of research involves creating and studying these hybrid organisms to understand complex biological processes and potentially develop new medical treatments. Chimeras have been used in various research studies, particularly in the fields of genetics, developmental biology, and regenerative medicine. Additionally, chimeras hold potential for organ transplant and disease modeling research. However, ethical considerations surrounding the creation and use of chimeras remain a major concern in this field.