Ethical, safety questions loom after first gene-edited baby is born in China
Chinese scientist Hu Jinakui says that he edited the genes of an embryo during in vitro fertilization and that the embryo grew to be a girl who was born in November. If his claims are true, the girl is the world's first genetically-modified human. Dr. Hu modified her genes to make her less likely to inherit the HIV virus from her father, who is HIV-positive. The techniques employed by Dr. Hu raise difficult ethical questions about the proper limits to genetically modifying humans. Plus, learn the English phrase "slippery slope."