The use of pigs for human transplants stems from a historical partnership between the Mayo Clinic and Hormel Foods to breed smaller 'minipigs' for lab research. This agricultural project, combined with pigs' anatomical similarities and lower disease-transmission risk compared to primates, established them as the primary source for replacement organs.

eGenesis prioritizes organs like kidneys and hearts because they show good outcomes in non-human primates and have high physiological similarity to humans. Livers are more challenging due to differences in synthetic function, dictating a different clinical approach (perfusion) instead of direct transplant.

Up to 40% of natural conceptions are spontaneously aborted, often before a woman knows she's pregnant. This is typically the body's way of rejecting embryos with severe genetic abnormalities. This natural process provides a powerful biological precedent for the practice of pre-implantation genetic screening.

Ophthalmology has become a "safe haven" for gene therapy because it mitigates the field's two main challenges: safety and manufacturing. Localized delivery to the immune-privileged eye improves the safety profile, while the thousand-fold lower required doses simplify manufacturing and dramatically improve the cost of goods.

A major unknown was the surgical procedure itself. After four cases, surgeons report that transplanting a pig kidney is remarkably similar to a human-to-human allogeneic transplant. This de-risks the surgical component significantly, with patients often leaving the ICU in one night.

Instead of using large commercial pigs and then editing genes to limit organ growth, eGenesis selected the Yucatan mini-pig breed from the start. This breed's organs naturally grow to a size compatible with human recipients, simplifying the genetic engineering required.

The field was stalled by the risk of transmitting porcine retroviruses to humans. The problem was intractable because 50-70 viral copies are spread across the pig genome. CRISPR's unique ability to efficiently make that many edits was the specific breakthrough needed to mitigate this key safety risk.

Unlike using genetically identical mice, Gordian tests therapies in large, genetically varied animals. This variation mimics human patient diversity, helping identify drugs that are effective across different biological profiles and addressing patient heterogeneity, a primary cause of clinical trial failure.

To get an unambiguous signal for their technology, Seek Labs targeted African Swine Fever, a virus with a guaranteed 100% death rate in pigs. This provided a definitive success metric (any survival) and avoided the complexities of modeling human diseases in animals.