“One month after an experimental procedure to transplant the heart of a genetically modified pig into a patient with end-stage heart disease, doctors say the heart is functioning on its own and shows no signs of rejection. … The pig heart used came from a genetically modified pig from Revivcor, a subsidiary the United Therapeutics Corporation. The pig had 10 genes edited, including three genes “knocked out” or inactivated to eliminate the alpha gal sugar in the pig’s blood cells, which can trigger a severe reaction in the human immune system, causing organ rejection. An additional pig gene was modified to control for the growth of the pig’s heart while six human genes were added into the pig’s genome to increase acceptance by the immune system.”

From CNN.