Chinese scientists have become the first in the world to inject an adult human with cells that have been genetically edited using the revolutionary CRISPR/Cas9 technique.
The CRISPR-edited cells were injected on October 28 by a team from the Sichuan University in Chengdu, as part of a clinical trial against aggressive lung cancer - and experts think it could trigger a biomedical race between the US and China.
If you haven't heard of CRISPR as yet, you soon will. The new gene-editing technique is poised to revolutionise the way we treat disease, by offering scientists a quick and easy way to cut and paste genes from our DNA.
CRISPR/Cas9 basically works like a pair of molecular scissors. Researchers just need to program it, and it can cut out certain genes - or add new ones - far more cheaply and quickly than any previous genetic tools.
Since the potential of the system was discovered back in 2012, it's already been tested widely in animals, and in January this year, it was used to successfully treat its first disease in mice, Duchenne muscular dystrophy.
There have also been CRISPR experiments done in non-viable human embryos, which were never brought to term.
But this is the first time that cells edited by CRISPR have ever been injected into an adult human.
The trial was carried out at the West China Hospital, and involved a patient with aggressive lung cancer. The researchers extracted the patient's immune cells from a blood sample and then used CRISPR editing to disable a gene in them.
The gene that was turned off codes for a protein called PD-1, which usually slows down a cell's immune response, allowing cancer to grow out of control.
These PD-1-free immune cells were then cultured in the lab and injected back into the patient. The aim is that they'll now proliferate in the patient's body and attack and destroy cancerous cells.
It's still early days, but lead researcher Lu You told David Cyranoski at Nature that the initial treatment went well, and the patient is now ready for a second injection.
Across the duration of the trial, which received ethics approval in July, the team aims to treat a total of 10 people, with between two and four injections of genetically edited immune cells each.
And they're not the only ones planning to use CRISPR on humans - the US has a similar trial against various cancers in the works, which is scheduled to start in early 2017, and has been funded by Napster billionaire Sean Parker.
And China has another three clinical trials planned for March 2017, which will investigate the use of CRISPR against bladder, prostate, and renal-cell cancers - although they're yet to receive funding and ethics approval for those.
All this activity leads experts to believe that we're in the midst of a new biomedical race between the US and China - like the space race, but this time the goal is efficient genetic editing.
"I think this is going to trigger 'Sputnik 2.0', a biomedical duel on progress between China and the United States," Carl June, an immunotherapist from the University of Pennsylvania and a scientific adviser on next year's US CRISPR trial, told Nature.
"[It's] important since competition usually improves the end product."
Other cancer researchers are excited about the progress, although it remains to be seen if the intensive process of individually removing, editing with CRISPR, and culturing patients' cells will be worth the end result.
This first Chinese trial will focus mainly on figuring out how safe the technique is, but hopefully in the coming months we'll also be able to get an idea of whether the technology works or not.
Either way, the fact that we're now able to edit people's genes so easily is a huge step forward for personalised medicine.
"The technology to be able to do this is incredible," Naiyer Rizvi from Columbia University Medical Centre, who wasn't involved in the study, told Nature.
The Chinese trial is still in the very early stages, and nothing has been published in a peer-reviewed journal as yet. But we'll be watching the results closely.