Is it possible to become immortal with the help of organ transplants? That was the unexpected topic of discussion this week between Chinese President Xi Jinping and Russian President Vladimir Putin when they met at a military parade in Beijing.
A translator, speaking in Mandarin on behalf of Putin, told Xi how human organs can be repeatedly transplanted so that one can get younger and younger in spite of age, and might even be able to stave off old age indefinitely.
It's predicted that in this century it might become possible to live to 150, he added.
Their smiles and laughter suggest it was a bit of banter, but might they be on to something?
Organ transplants certainly save lives - in the UK, over 100,000 people have been saved in the last 30 years, says NHS Blood and Transplant.
And continued advancements in medicine and technology mean transplanted organs are lasting far longer once in people.
Some patients have had a kidney transplant that has kept working for more than 50 years.
The lifespan of an organ depends on the health of both the donor and recipient, as well as how well they care for it.
For instance, you could expect a new kidney from a living donor to last around 20-25 years, while one from a deceased donor may last 15-20 years.
The type of organ matters too; a liver might last around 20 years, a heart about 15 years, and lungs nearly 10 years.
Putin and Xi may be talking about having multiple organs transplanted and perhaps repeatedly.
However, undergoing surgery carries significant risks. Each time patients go under the knife, they risk complications.
Currently, organ recipients must take strong immunosuppressants for life to prevent rejection, which can have severe side effects and increase the risk of infections.
As of now, scientists are exploring xenotransplantation with genetically altered pigs to create organs that are compatible with human biology.
Though still experimental, this research represents a potential breakthrough in overcoming organ transplant rejection.
While developing new organs using stem cells promises an exciting future, the focus remains on treating diseases rather than extending lifespan far beyond natural limits.
So, while there's ongoing research into extending human life, pronounced changes in this domain - such as effectively achieving immortality - remain within the realm of speculation.
Prof. Mabbott expresses skepticism regarding living up to 150 years without serious health complications, emphasizing the need for quality of life rather than merely extending quantity. As research advances, the ethical implications and practical realities of such ideas will demand our scrutiny.