A 53-year-old man in Germany has become at least the third person with HIV to be declared clear of the virus after his bone marrow cells were replaced with HIV-resistant stem cells from a donor with a genetic mutation that makes cells resistant to the virus. While antiretroviral therapy (ART) has been given to people with HIV for years, it does not eliminate the virus from the body. A true cure would eliminate this reservoir, and this is what seems to have happened for the 'Düsseldorf' patient, who stopped taking ART in 2018 and has remained HIV-free since. His cancerous bone marrow cells were replaced after he was diagnosed with acute myeloid leukaemia in 2013. Virologist Björn-Erik Jensen at Düsseldorf University Hospital says his team has done transplants for several other people affected by both HIV and cancer, using stem cells with the same mutation, but it is too early to say if those individuals are virus-free.