From the Greek word xenos, meaning “stranger.” Xenogeneic literally means “strange genes.” Refers to genetically engineered (e.g., “humanized”) organs that have been grown within an animal of another species. For example, several companies are working to engineer and grow—inside swine—a number of organs to be transplanted into humans that need those organs (e.g., due to loss of their own organs via disease or accident). If successful, this would free human organ transplant recipients from having to continually use immunosuppressive drugs in order to keep their body from “rejecting” the new organ.