3 Human Chimeras That Already Exist

For example, in 2002, news outlets reported the story of a woman named Karen Keegan, who needed a kidney transplant and underwent genetic testing along with her family, to see if a family member could donate one to her. The mystery was solved when doctors discovered that Keegan was a chimera — the set of DNA in her blood cells was different from that in the other tissues in her body. A person can also be a chimera if he or she undergoes a bone marrow transplant.