Chances are, you know someone who has required an organ transplant. You might have even had one yourself. Whether it’s a liver or a slab of skin, organs are hard to come by. Around 150,000 people die every day, but only a fraction are organ donors. 

Once a patient goes on the transplant list, they are ranked by severity of their condition and are matched with a donor who has the same blood and tissue type, the time they have spent on the waiting list, and in some cases, previous addictions. Race, ethnic background, economic status, and social status are not considered. When an organ is donated close to a patient, they get special preference; using a local organ has a lesser chance of being rejected by the recipient if less time is taken between the death of the donor and the transplantation of the organ.

Scientists have been working diligently to find a way to grow human cells within another species to make transplant organs more easy to come by. This week, scientists succeeded in making the first human-pig embryos. Although the experiment’s results were quickly destroyed, this small success is a large step in the direction of creating more organs for those in need. 

This groundbreaking experiment established its roots with much smaller ones. Scientists first began by melding the embryos of mice and rats. This was thought to be easier due to the similarities between the species. Researchers at Stanford bred mice who did not have a pancreas, attempting to grow the missing pancreas with stem cells from a rat. This attempt was successful. The mutant mouse grew a healthy pancreas and lived the normal amount of time for its species.

Although these preliminary studies look promising, there is still much more undiscovered ground to tread. Twenty-two people die every day from lack of an organ; eventually, this number will be reduced to zero.