According to foreign media news, researchers reported on July 27 that a 66 year old leukemia patient had long-term remission of AIDS after receiving stem cell transplantation, or had achieved "cure". This is the fourth "cured" AIDS patient in the world and the oldest patient at present. This patient was treated at the city of Hope Medical Center in Duarte, California, USA. Because he did not want to be named, he was called the "city of hope" patient. At present, he has not received antiretroviral therapy (Art) for 17 months, but there is no sign of AIDS virus (HIV) replication in his body. In addition to being the oldest, this patient also had the longest time of HIV infection. He was diagnosed with AIDS in1988. For 30 years, he has been receiving art to control his condition, but failed to effectively treat HIV. In 2018, the patient developed acute myeloid leukemia (AML), a blood and bone marrow cancer. He received chemotherapy to relieve leukemia. Due to his age, he received lower intensity chemotherapy to prepare for stem cell transplantation. Subsequently, doctors performed hematopoietic stem cell transplantation with cells from donors carrying rare gene mutations. This mutation, called homozygous CCR5 delta 32, makes its carriers resistant to HIV by changing the entry of the virus into human leukocytes. This is an improved treatment of hematopoietic stem cell transplantation, which can be better tolerated by the elderly with blood cancer and reduce the possibility of transplant related complications. This method first cured "Berlin patient" Timothy Ray Brown in 2007. This "city of hope" patient stopped receiving art in March 2021. The team said that his AIDS and leukemia had been alleviated for more than a year. Researchers submitted data to the 24th International AIDS conference held on July 29. They said that this case has brought the possibility of cure for elderly patients with AIDS and blood cancer, especially when the donor is not a family member. Sharon Levin, President designate of the international AIDS Association, said that this case provided "continuous hope and encouragement" for HIV carriers and the wider scientific community, although it is unlikely to become the choice of most HIV carriers due to the risk of surgery. Researchers believe that this process is effective because the donor's stem cells have a special and rare genetic mutation, which means that they lack the receptor that HIV uses to infect cells. On July 27, Spanish researchers also released the details of a 59 year old woman, who is one of the few known as "post-treatment controller". Levin said that although she stopped receiving art, the virus load in her body remained undetectable for 15 years, which could provide clues for a potential cure. (outlook new era)