Currently in the U.S., there is a tremendous unmet demand for transplant organs with over 118,000 people in need of a lifesaving organ transplant. Of those, over 75,000 people are active waiting list candidates. The concept of cross-species transplantation, known as xenotransplantation, is the transfer of living cells, tissues or organs from one species to another. Due to the shortage of human organs, xenotransplantation emerged as an alternative potential option and its clinical potential is being explored with new technologies such as CRISPR Cas-9. Xenotransplantation is not new -- the first serious attempts (then called heterotransplantation) first appeared in the scientific literature in 1905 and has been explored with limited success over the last century.