Scientists have recently found what they believe to be the cure to HIV, a man in London who was diagnosed with the virus in 2003 is currently in remission after receiving a special bone marrow transplant intended to treat cancer.

In 2016, he received the stem cell transplant from a donor, with a rare CCR5 mutation that allows HIV resistance, to treat his Hodgkin’s lymphoma. But the anonymous man isn’t the first person to allegedly be cured of HIV. Back in 2007, a Berlin man became HIV-free after receiving the same transplant.

“By achieving [HIV] remission in a second patient using a similar approach, we have shown that the Berlin patient was not an anomaly, and that it really was the treatment that eliminated HIV in these two people.”