A scientific breakthrough means we are another step closer to starting transplants of pig organs to humans.
US scientists have been able to remove viruses from pig DNA, which was one of the largest obstacles standing in the way of the transplants.
Researchers at eGenesis claim this is an exciting and promising step, according to the BBC.
However, they have admitted that there are still huge issues ahead in the research as it is not yet known how to stop humans from rejecting pig organs.
The research involved working with the genetic code in the pigs and mixing both human and pig cells together to discover whether the viruses would infect humans.
As the viruses could infect human tissue, scientists were then able to use gene-editing technology known as Crispr to remove the viruses.
By using the same technology used to create Dolly the sheep, the new genetic information could be placed into a pig's egg to form embryos.
Although this process did not always work, 37 pigs were born with the new genetic information.
Harvard University researcher doctor Luhan Yang told the BBC that the pigs are the most genetically modified in existence.
Researchers believe pigs are a good candidate for organs to be transferred to humans as their organs are a similar size and they can be bred in large numbers.