https://www.vice.com/en_us/article/5dgm3k/pig-kidney-successfully-transplanted-from-hog-to-human > Doctors in New York City transplanted a kidney grown in a pig to a brain-dead woman in a major step forward for xenotransplantation, a process in which human organs are grown in animals and then transplanted into humans. The kidney functioned normally and processed urine for 54 hours before the woman was removed from a ventilator and died.  > The procedure is the most significant xenotransplantation experiment ever done, and a step toward what many scientists believe is one of two potential future processes that could help supply enough organs to patients who are on the extremely long transplantation lists. Roughly 106,000 Americans are estimated to be waiting for organs needed for life-saving transplantation procedures. Some futurists believe that we will eventually grow organs in a laboratory or print them using advanced 3D bioprinters; others believe that we can grow human organs in genetically modified pigs, then transplant them into humans.