A U.S. patient with leukemia has become the first woman and the third person in the world to be cured of HIV after receiving a stem cell transplant from a donor who was naturally resistant to the virus that causes AIDS, researchers reported on Tuesday February 15.

The case of a 64-year-old woman of mixed race, presented at the Conference on Retroviruses and Opportunisitic Infections in Denver, is also the first involving umbilical cord blood, a newer approach that may make the treatment available to more people.

Since receiving the cord blood to treat her acute myeloid leukemia,  a cancer that starts in blood-forming cells in the bone marrow,  the woman has been in remission and free of the virus for 14 months, without the need for potent HIV treatments known as antiretroviral therapy.

The two prior cases occurred in males, one white and one Latino, who had received adult stem cells, which are more frequently used in bone marrow transplants.

“This is now the third report of a cure in this setting, and the first in a woman living with HIV,” Sharon Lewin, President-Elect of the International AIDS Society, said in a statement.

The case is part of a larger U.S.-backed study led by Dr. Yvonne Bryson of the University of California Los Angeles (UCLA), and Dr. Deborah Persaud of Johns Hopkins University in Baltimore.

The woman in question was diagnosed with HIV in 2013 and leukemia in 2017, making her a potential candidate.

She received the treatment four years ago, and in the time since her cancer has gone into remission, and her HIV treatment was discontinued last winter.

Her body reacted well to the treatment, the doctors report, and she quickly saw positive results.

Despite dropping HIV treatment over a year ago, the virus has not resurged in her. Repeated scans of her body show no HIV cells with the potential of replicating.  They also drew cells from her body and attempted to infect them in a laboratory, and failed.

If a few more years pass and doctors still fail to find any HIV in her body and fail to infect her cells, then they will declare her ‘cured’ of the virus.

“I’m excited that it’s turned out so well for her,” Dr Yvonne Bryson told NBC.

She added that the New York patient’s case has added “more hope and more options for the future’ of HIV treatment.