(AP) — Scientists are reporting the first use of the gene-editing tool CRISPR to try to cure a patient’s HIV infection by providing blood cells that were altered to resist the AIDS virus.

The gene-editing tool has long been used in research labs.

Wednesday’s report in the New England Journal of Medicine, by Chinese researchers, is the first published account of using CRISPR to treat a disease in an adult, where the DNA changes are confined to that person.

The attempt was successful in some ways but fell short of being an HIV cure.

Still, it shows that gene editing holds promise and seems precise and safe in this patient so far, said Dr. Carl June, a University of Pennsylvania genetics expert.

“That’s really good for the field,” June said.

Chinese government grants paid for the research, which was done openly with advance notice on a scientific registry and standard informed consent procedures.

Gene editing permanently alters DNA, the code of life. CRISPR is a relatively new tool scientists can use to cut DNA at a specific spot.

The new case involves a 27-year-old man with HIV who needed a blood stem cell transplant to treat cancer. Previously, two other men were apparently cured of both diseases by transplants from donors with natural resistance to HIV because they have a gene mutation that prevents HIV from entering cells. Since donors like this are very rare, the Chinese scientists tried to create similar HIV resistance by “editing” that gene in blood cells in the lab to try to mimic the mutation.

The transplant put the man’s cancer in remission, and the cells that were altered to resist HIV are still working 19 months later. But they comprise only 5% to 8% of such blood cells, so they’re outnumbered by ones that can still be infected.

“They need to approach 90% or more, I think, to actually have a chance of curing HIV,” June said.