In this case, however, there was a second goal: to cure the patient's HIV.
The patient received stem cells three years ago from an HIV-resistant donor and then went off his medication that is meant to keep the disease from growing inside the body, also known as antiretroviral treatment or ART.
Combined with past cases (one successful and one failed), we can now say something about what needs to be done to get rid of the virus.
The transplant changed the London patient's immune system, giving him the donor's mutation and HIV resistance.
His case was published in Nature journal yesterday, and simultaneously announced by University College London researchers at the annual Conference on Retroviruses and Opportunistic Infections in Seattle.
But he added: "The treatment is not appropriate as a standard HIV treatment because of the toxicity of chemotherapy, which in this case was required to treat the lymphoma".
Professor Eduardo Olavarria, from Imperial College London, said: "While it is too premature to say with certainty that our patient is now cured of HIV, he is clearly in a long-term remission".
London HIV patient becomes world's second AIDS cure hope
In the meantime, he said the focus needed to be on diagnosing HIV promptly and starting patients on lifelong combination antiretroviral therapy.
Some 37 million people worldwide are now infected with HIV, and the AIDS pandemic has killed about 35 million people worldwide since it began in the 1980s.
Dr. Gero Hütter, who treated the Berlin patient and is now medical director at Cellex Collection Center in Dresden, Germany, said in an email that the treatment used for the London patient is "comparable" to the one he pioneered. People who have two mutated copies of the CCR5 allele are resistant to the HIV-1 virus strain that uses this receptor, as the virus can not enter host cells.
The new report shows that doctors don't have to use as intense a treatment regime as the Berlin patient underwent in order to achieve success. After two bone marrow transplants, Brown was considered cured of his HIV-1 infection.
But a second instance of remission and likely cure following such a transplant will help scientists narrow the range of treatment strategies, he and others said. About 1 percent of people descended from northern Europeans have inherited the mutation from both parents and are immune to most HIV. Notable differences were that the Berlin Patient was given two transplants and underwent total body irradiation, while the United Kingdom patient received just one transplant and less intensive chemotherapy. Scientists have wondered, however, whether this good fortune could be shared around by injecting stem cells from people with two Δ32 copies into HIV patients.
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A number of opinion polls indicate Mr Trudeau's popularity is slipping in the run-up to a general election scheduled for October. Wilson-Raybould announced her resignation from federal cabinet on February 12. "I want to thank her for her service", he said.