While the system would be potentially useful for human organ transplantation and could save more lives as a result, it doesn’t address the biggest ethical issue of consent, says Hank Greely, a Stanford law and ethics professor who reviewed the 2019 findings but was not involved in the latest OrganEx research.

“If you do this in humans, it’ll be really important that people are told not just that they’re volunteering to have their organs transplanted, but to have their bodies kept alive for an indeterminate period of time to assist in that transplantation,” he says. “But this doesn’t answer the questions left open by the pig brain experiment: Can you really bring the brain back to life? They’re resolutely not looking for the answer to that question.”