Braving a funding ban put in place by America’s top health agency, some U.S. research centers are moving ahead with attempts to grow human tissue inside pigs and sheep with the goal of creating hearts, livers, or other organs needed for transplants.
The effort to incubate organs in farm animals is ethically charged because it involves adding human cells to animal embryos in ways that could blur the line between species.
One researcher, Juan Carlos Izpisua Belmonte of the Salk Institute, showed unpublished data on more than a dozen pig embryo containing human cells.
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