The first person cured of HIV, Timothy Ray Brown, has died at the age of 54, the International AIDS Society said in a statement on Wednesday.
Brown died after his leukemia returned six months ago and spread to his spine and brain.
He was initially known by the pseudonym of the "Berlin patient" after he was cured of HIV in 2008, but later decided to campaign publicly under his own name.
Brown died in his home in Palm Springs in the US state of California, The New York Times reported, citing his partner Tim Hoeffgen.
Brown was born in Seattle, on the west coast of the US, and moved to Berlin in 1993, where he studied and worked in a cafe and as a translator.
He was diagnosed with HIV in 1995. When he became ill with leukemia in 2006, he needed a stem cell transplant.
Donor with a mutation
Doctors from Berlin's Charite hospital found a donor with a mutation in the so-called CCR5 gene which made him naturally resistant to HIV infection.
After the risky transplant, the virus was no longer detected in Brown, and he remained HIV-free for the remainder of his life.
He later called the date of the transplant, 6 February 6 2007, his new birthday.
Though such a transplant is not a viable large-scale treatment, Brown's case sparked hope that HIV may one day be widely curable and fuelled efforts by researchers and institutions.
"We owe Timothy and his doctor, Gero Huetter, a great deal of gratitude for opening the door for scientists to explore the concept that a cure for HIV is possible," IAS president Adeeba Kamarulzaman said.