[1] As of 2016[update], he was a controversial figure as he announced his intent to perform a human head transplant, an operation that has never been done before.
Prior to his announcement of attempting the first human head transplant, Ren had spent years performing the same surgery on mice.
[5] Dr. Hunt Batjer, past-President of the Congress of Neurological Surgeons, has stated in reference to the surgery that he "would not allow anyone to do it to me as there are a lot of things worse than death."
[7] In November 2017, Sergio Canavero claimed that a team led by Ren had performed the first successful human head transplant.
Spiridonov has expressed hope that Ren and Canavero would provide more transparency into "what went wrong in China and why.