Canavero and Ren recently performed a trial run on two cadavers, prompting outrage from the medical community, which has declared human head transplantation “fake news.” An examination by a team of independent scientists published this month, however, suggests that, while fantastical seeming, the scientific and medical advancements necessary for human head transplantation are rapidly approaching plausibility. Nevertheless, major ethical and moral hurdles remain.

Canavero has been talking up his plan for human head transplantation in TED talks and the media for decades, despite producing little in the way of scientific evidence, going so far as to announce in 2015 that he would perform surgery on a human volunteer — a young man with Werdnig-Hoffman disease, a degenerative disease where the muscles waste away — by 2017. The volunteer backed out, and the surgery still hasn’t been done on a living human, but Canavero maintains that it is “imminent.” Together he and Ren devised a procedure for head transplantation, which they performed in a handful of animal studies on mice, rats and a dog, all of whom shockingly survived the surgery and even regained some motor function.