A team of researchers from Scotland made news with that very product, but the truth of what they’ve done, or could do, is much more complex, interesting, and, potentially, real. A new study from those researchers, who are based at the University of Edinburgh, says they’ve created something curious: a “chicken bioreactor.

These researchers are based at the Roslin Institute, a research facility within the University of Edinburgh system that focuses on animal genetics. Their best-known work? Dolly the freaking sheep.

This chicken bioreactor is an attempt to figure out a way to cheaply and efficiently produce a variety of protein drugs. Proteins have for a few decades now been a major focus of research into fighting cancer; certain kinds of proteins can encourage the growth of cancer, and researchers are looking at ways that other proteins can counteract that growth. Protein drugs are sometimes referred to as “targeted” drugs for cancers and tumors, specifically aimed at controlling a cancer rather than simply killing all nearby cells, as chemotherapy does.

This isn’t new stuff, and it isn’t under-the-radar; the FDA approved a whopping 62 of these drugs for cancer treatment, among other uses, between 2011 and 2016. The problem isn’t that protein drugs are new, it’s that they’re kind of expensive to produce. That’s where chickens come in.

Livestock has shown the ability to serve as little pharmaceutical factories when genetically modified. In 2009, the FDA approved the first such drug, a blood thinner produced by a GMO goat which has been modified with human genes. (The proteins are extracted from the goat’s milk.) This new chicken work is in the same vein, except instead of goat’s milk, it’s eggs.

This new research causes chickens to produce valuable protein drugs that are expressed in the whites of their eggs. (Apparently it does not cause any harm to the chickens; they just lay eggs as usual.) According to the researchers, the cost could be anywhere from 10 to 100 times cheaper than other methods. Using chickens in this way is less common than with mammals, though there is another approved chicken-produced drug to treat a condition called lysosomal acid lipase deficiency. This new work, though, could be a huge step forward; LAL-D only affects about one in 40,000 people, while the drugs produced by these new GMO chickens could treat much more common ailments.