Two 'chimera' piglets containing the DNA of both monkeys and pigs have been born in a laboratory in China.
Both piglets looked like piglets, but - in actual fact - their make-up contained genetic material from cynomolgus monkeys in key parts of their body such as the heart, lungs, liver, spleen, and skin.
Scientists claim that the research, which used more than 4,000 embryos to create the two piglets, will help further research to find ways of growing human organs in animals for transplants.
Both piglets died within a week.
Tang Hai, from the State Key Laboratory of Stem Cell and Reproductive Biology in Beijing told New Scientist: "This is the first report of full-term monkey-pig chimeras."
So, how does one even go about this ethically confusing process?
Well, it's obviously quite difficult.
The five day old piglet embryos - thousands of them, remember? - were injected with monkey stem cells that had been modified to contain a fluorescent protein.
That meant that when the scientists performed observations they could see where they'd ended up.
Whilst those responsible couldn't be sure why the piglets died, they reckon it's something to do with the IVF process rather than the chimerism, as eight other piglets that were also implanted died as well.
Obviously, this sort of science is something of a concern for many others within the community who see it as an ethical dilemma.
One neuroscientist, Douglas Munoz from Queen's University in Kingston, Canada, said that this sort of science "just ethically really scares me".
He continued: "For us to start to manipulate life functions in this kind of way without fully knowing how to turn it off, or stop it if something goes awry really scares me."
Quandaries such as this one seem to fall on deaf ears when it comes to China, however.
As well as allowing this controversial project to continue, they're also looking at creating monkeys with partially human-derived brains to get a better handle on diseases such as Alzheimer's.
We could use the help, too.
If this science is to be used to grow organs, it could mean that non-human organ donation is possible, which would ease the burden and create an alternative to human donation.
Yale University stem cell expert Alejandro De Los Angeles said that the research into an improved animal model for human diseases is the "holy grail" of biomedical research and has been for many years.
He added: "Realising the promise of human-monkey chimera research in an ethically and scientifically appropriate manner will require a coordinated approach."
Whether or not we're at that point yet isn't clear.
Featured Image Credit: Tang HaiTopics: Science, World News, Interesting, Weird