There's also a concern based more in science fiction than reality, but here goes: What if those human cells somehow migrate to the developing pig's brain and make it more human? Like, pigs with human hair, reproductive cells, or the most extreme scenario, a real Babe?
In 2015, the NIH banned taxpayer funding for chimera research, which it moved to lift in 2016 -- predictably, groups like the US Conference of Catholic Bishops and PETA aren't keen on the idea.
Dr. Wu says the funding ax has greatly affected chimera research. Getting enough functional cells for clinical use is often costly, and therefore impractical.
"Working with large animals such as the pig is rather expensive, and continued funding will greatly facilitate our project," he says. "We have to resort to other funding sources for continued research."
He claims the team is working responsibly, reassuring the skeptics that creating the pig from Animal Farm is just as crazy as it sounds.
"At this stage, we only allow the gestation to continue no more than four weeks, when the pig brain is far from fully developed and therefore the chances of an animal gaining human consciousness is basically zero," he explains. "Besides, the human cell contribution to the whole pig embryo at this stage is very low, less than 0.01%. The NIH's concern is only valid if a significant amount of human cells can contribute to pig brain development and, based on our preliminary results, this outcome is unlikely."